[HOTFIX] Ignore all Docker integration tests

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.

external/docker-integration-tests/src/test/scala/org/apache/spark/sql/jdbc/MySQLIntegrationSuite.scala

@@ -21,9 +21,12 @@ import java.math.BigDecimal
 import java.sql.{Connection, Date, Timestamp}
 import java.util.Properties
 
+import org.scalatest.Ignore
+
 import org.apache.spark.tags.DockerTest
 
 @DockerTest
+@Ignore
 class MySQLIntegrationSuite extends DockerJDBCIntegrationSuite {
   override val db = new DatabaseOnDocker {
     override val imageName = "mysql:5.7.9"

external/docker-integration-tests/src/test/scala/org/apache/spark/sql/jdbc/OracleIntegrationSuite.scala

@@ -20,6 +20,8 @@ package org.apache.spark.sql.jdbc
 import java.sql.Connection
 import java.util.Properties
 
+import org.scalatest.Ignore
+
 import org.apache.spark.sql.test.SharedSQLContext
 import org.apache.spark.tags.DockerTest
 
@@ -44,6 +46,7 @@ import org.apache.spark.tags.DockerTest
  * repository.
  */
 @DockerTest
+@Ignore
 class OracleIntegrationSuite extends DockerJDBCIntegrationSuite with SharedSQLContext {
   import testImplicits._
 

external/docker-integration-tests/src/test/scala/org/apache/spark/sql/jdbc/PostgresIntegrationSuite.scala

@@ -20,12 +20,15 @@ package org.apache.spark.sql.jdbc
 import java.sql.Connection
 import java.util.Properties
 
+import org.scalatest.Ignore
+
 import org.apache.spark.sql.Column
 import org.apache.spark.sql.catalyst.expressions.Literal
 import org.apache.spark.sql.types.{ArrayType, DecimalType}
 import org.apache.spark.tags.DockerTest
 
 @DockerTest
+@Ignore
 class PostgresIntegrationSuite extends DockerJDBCIntegrationSuite {
   override val db = new DatabaseOnDocker {
     override val imageName = "postgres:9.4.5"