This patch bumps the master branch version to `2.3.0-SNAPSHOT`.

Author: Josh Rosen <joshrosen@databricks.com>

Closes #17753 from JoshRosen/SPARK-20453.

[SPARK-19318][SQL] Fix to treat JDBC connection properties specified by the user in case-sensitive manner.

## What changes were proposed in this pull request?
The reason for test failure is that the property “oracle.jdbc.mapDateToTimestamp” set by the test was getting converted into all lower case. Oracle database expects this property in case-sensitive manner.

This test was passing in previous releases because connection properties were sent as user specified for the test case scenario. Fixes to handle all option uniformly in case-insensitive manner, converted the JDBC connection properties also to lower case.

This PR  enhances CaseInsensitiveMap to keep track of input case-sensitive keys , and uses those when creating connection properties that are passed to the JDBC connection.

Alternative approach PR https://github.com/apache/spark/pull/16847  is to pass original input keys to JDBC data source by adding check in the  Data source class and handle case-insensitivity in the JDBC source code.

## How was this patch tested?
Added new test cases to JdbcSuite , and OracleIntegrationSuite. Ran docker integration tests passed on my laptop, all tests passed successfully.

Author: sureshthalamati <suresh.thalamati@gmail.com>

Closes #16891 from sureshthalamati/jdbc_case_senstivity_props_fix-SPARK-19318.

## What changes were proposed in this pull request?

JDBC  read  is failing with  NPE due to missing null value check for array data type if the source table has null values in the array type column.  For null values Resultset.getArray()  returns null.
This PR adds null safe check to the Resultset.getArray() value before invoking method on the Array object.
## How was this patch tested?

Updated the PostgresIntegration test suite to test null values. Ran docker integration tests on my laptop.

Author: sureshthalamati <suresh.thalamati@gmail.com>

Closes #15192 from sureshthalamati/jdbc_array_null_fix-SPARK-14536.

Remove spark-tag's compile-scope dependency (and, indirectly, spark-core's compile-scope transitive-dependency) on scalatest by splitting test-oriented tags into spark-tags' test JAR.

Alternative to #16303.

Author: Ryan Williams <ryan.blake.williams@gmail.com>

Closes #16311 from ryan-williams/tt.

## What changes were proposed in this pull request?
This patch bumps master branch version to 2.2.0-SNAPSHOT.

## How was this patch tested?
N/A

Author: Reynold Xin <rxin@databricks.com>

Closes #16126 from rxin/SPARK-18695.

[SPARK-17803: Docker integration tests don't run with "Docker for Mac"](https://issues.apache.org/jira/browse/SPARK-17803)

## What changes were proposed in this pull request?

This PR upgrades the [docker-client](https://mvnrepository.com/artifact/com.spotify/docker-client) dependency from [3.6.6](https://mvnrepository.com/artifact/com.spotify/docker-client/3.6.6) to [5.0.2](https://mvnrepository.com/artifact/com.spotify/docker-client/5.0.2) to enable _Docker for Mac_ users to run the `docker-integration-tests` out of the box.

The very latest docker-client version is [6.0.0](https://mvnrepository.com/artifact/com.spotify/docker-client/6.0.0) but that has one additional dependency and no usage yet.

## How was this patch tested?

The code change was tested on Mac OS X Yosemite with both _Docker Toolbox_ as well as _Docker for Mac_ and on Linux Ubuntu 14.04.

```
$ build/mvn -Pyarn -Phadoop-2.6 -Dhadoop.version=2.6.0 -Phive -Phive-thriftserver -DskipTests clean package

$ build/mvn -Pdocker-integration-tests -Pscala-2.11 -pl :spark-docker-integration-tests_2.11 clean compile test
```

Author: Christian Kadner <ckadner@us.ibm.com>

Closes #15378 from ckadner/SPARK-17803_Docker_for_Mac.

## What changes were proposed in this pull request?
Docker tests are using older version  of jersey jars (1.19),  which was used in older releases of spark.  In 2.0 releases Spark was upgraded to use 2.x verison of Jersey. After  upgrade to new versions, docker tests  are  failing with AbstractMethodError.  Now that spark is upgraded  to 2.x jersey version, using of  shaded docker jars  may not be required any more.  Removed the exclusions/overrides of jersey related classes from pom file, and changed the docker-client to use regular jar instead of shaded one.

## How was this patch tested?

Tested  using existing  docker-integration-tests

Author: sureshthalamati <suresh.thalamati@gmail.com>

Closes #15114 from sureshthalamati/docker_testfix-spark-17473.

## What changes were proposed in this pull request?

When reading float4 and smallint columns from PostgreSQL, Spark's `PostgresDialect` widens these types to Decimal and Integer rather than using the narrower Float and Short types. According to https://www.postgresql.org/docs/7.1/static/datatype.html#DATATYPE-TABLE, Postgres maps the `smallint` type to a signed two-byte integer and the `real` / `float4` types to single precision floating point numbers.

This patch fixes this by adding more special-cases to `getCatalystType`, similar to what was done for the Derby JDBC dialect. I also fixed a similar problem in the write path which causes Spark to create integer columns in Postgres for what should have been ShortType columns.

## How was this patch tested?

New test cases in `PostgresIntegrationSuite` (which I ran manually because Jenkins can't run it right now).

Author: Josh Rosen <joshrosen@databricks.com>

Closes #14796 from JoshRosen/postgres-jdbc-type-fixes.

## What changes were proposed in this pull request?

Spark will convert **BooleanType** to **BIT(1)**, **LongType** to **BIGINT**, **ByteType**  to **BYTE** when saving DataFrame to Oracle, but Oracle does not support BIT, BIGINT and BYTE types.

This PR is convert following _Spark Types_ to _Oracle types_ refer to [Oracle Developer's Guide](https://docs.oracle.com/cd/E19501-01/819-3659/gcmaz/)

Spark Type | Oracle
----|----
BooleanType | NUMBER(1)
IntegerType | NUMBER(10)
LongType | NUMBER(19)
FloatType | NUMBER(19, 4)
DoubleType | NUMBER(19, 4)
ByteType | NUMBER(3)
ShortType | NUMBER(5)

## How was this patch tested?

Add new tests in [JDBCSuite.scala](https://github.com/wangyum/spark/commit/22b0c2a4228cb8b5098ad741ddf4d1904e745ff6#diff-dc4b58851b084b274df6fe6b189db84d) and [OracleDialect.scala](https://github.com/wangyum/spark/commit/22b0c2a4228cb8b5098ad741ddf4d1904e745ff6#diff-5e0cadf526662f9281aa26315b3750ad)

Author: Yuming Wang <wgyumg@gmail.com>

Closes #14377 from wangyum/SPARK-16625.

## What changes were proposed in this pull request?
After SPARK-16476 (committed earlier today as #14128), we can finally bump the version number.

## How was this patch tested?
N/A

Author: Reynold Xin <rxin@databricks.com>

Closes #14130 from rxin/SPARK-16477.

## What changes were proposed in this pull request?

(See https://github.com/apache/spark/pull/12416 where most of this was already reviewed and committed; this is just the module structure and move part. This change does not move the annotations into test scope, which was the apparently problem last time.)

Rename `spark-test-tags` -> `spark-tags`; move common annotations like `Since` to `spark-tags`

## How was this patch tested?

Jenkins tests.

Author: Sean Owen <sowen@cloudera.com>

Closes #13074 from srowen/SPARK-15290.

## What changes were proposed in this pull request?

(Retry of https://github.com/apache/spark/pull/13049)

- update to httpclient 4.5 / httpcore 4.4
- remove some defunct exclusions
- manage httpmime version to match
- update selenium / httpunit to support 4.5 (possible now that Jetty 9 is used)

## How was this patch tested?

Jenkins tests. Also, locally running the same test command of one Jenkins profile that failed: `mvn -Phadoop-2.6 -Pyarn -Phive -Phive-thriftserver -Pkinesis-asl ...`

Author: Sean Owen <sowen@cloudera.com>

Closes #13117 from srowen/SPARK-12972.2.

This reverts commit c74a6c3f.

## What changes were proposed in this pull request?

- update httpcore/httpclient to latest
- centralize version management
- remove excludes that are no longer relevant according to SBT/Maven dep graphs
- also manage httpmime to match httpclient

## How was this patch tested?

Jenkins tests, plus review of dependency graphs from SBT/Maven, and review of test-dependencies.sh  output

Author: Sean Owen <sowen@cloudera.com>

Closes #13049 from srowen/SPARK-12972.

## What changes were proposed in this pull request?

Create a maven profile for executing the docker integration tests using maven
Remove docker integration tests from main sbt build
Update documentation on how to run docker integration tests from sbt

## How was this patch tested?

Manual test of the docker integration tests as in :
mvn -Pdocker-integration-tests -pl :spark-docker-integration-tests_2.11 compile test

## Other comments

Note that the the DB2 Docker Tests are still disabled as there is a kernel version issue on the AMPLab Jenkins slaves and we would need to get them on the right level before enabling those tests. They do run ok locally with the updates from PR #12348

Author: Luciano Resende <lresende@apache.org>

Closes #12508 from lresende/docker.

## What changes were proposed in this pull request?

Enhance the DB2 JDBC Dialect docker tests as they seemed to have had some issues on previous merge causing some tests to fail.

## How was this patch tested?

By running the integration tests locally.

Author: Luciano Resende <lresende@apache.org>

Closes #12348 from lresende/SPARK-14589.

This reverts commit dae538a4.

## What changes were proposed in this pull request?

This PR adds `since` tag into the matrix and vector classes in spark-mllib-local.

## How was this patch tested?

Scala-style checks passed.

Author: Pravin Gadakh <prgadakh@in.ibm.com>

Closes #12416 from pravingadakh/SPARK-14613.

The Docker integration tests are failing very often (https://spark-tests.appspot.com/failed-tests) so I think we should disable these suites for now until we have time to improve them.

Author: Josh Rosen <joshrosen@databricks.com>

Closes #12549 from JoshRosen/ignore-all-docker-tests.

## What changes were proposed in this pull request?

Enable Oracle docker tests

## How was this patch tested?

Existing tests

Author: Luciano Resende <lresende@apache.org>

Closes #12270 from lresende/oracle.

Add integration tests based on docker to test DB2 JDBC dialect support

Author: Luciano Resende <lresende@apache.org>

Closes #9893 from lresende/SPARK-10521.

## What changes were proposed in this pull request?

Move `docker` dirs out of top level into `external/`; move `extras/*` into `external/`

## How was this patch tested?

This is tested with Jenkins tests.

Author: Sean Owen <sowen@cloudera.com>

Closes #11523 from srowen/SPARK-13595.