[HOTFIX][SPARK-4123]: Updated to fix bug where multiple dependencies added breaks Github output

Currently there is a bug whereby if a new patch introduces more than one new dependency (or removes more than one) it breaks the Github post output (see [this build](https://amplab.cs.berkeley.edu/jenkins/job/SparkPullRequestBuilder/29399/consoleFull)). This hotfix will remove `awk` print statements in place of `printf` so as not to automatically add the newline character which is then escaped and added directly at the end of the `awk` statement. This should take a failed build output such as:

```json
data: {"body": "  [Test build #29400 has finished](https://amplab.cs.berkeley.edu/jenkins/job/SparkPullRequestBuilder/29400/consoleFull) for   PR 5266 at commit [`2aa4be0`](https://github.com/apache/spark/commit/2aa4be0e1d7ce052f8c901c6d9462c611c3a920a).\n * This patch **passes all tests**.\n * This patch merges cleanly.\n * This patch adds the following public classes _(experimental)_:\n  * `class IDF extends Estimator[IDFModel] with IDFParams `\n  * `class Normalizer extends UnaryTransformer[Vector, Vector, Normalizer] `\n\n * This patch **adds the following new dependencies:**\n   * `avro-1.7.7.jar`
   * `breeze-macros_2.10-0.11.2.jar`
   * `breeze_2.10-0.11.2.jar`\n * This patch **removes the following dependencies:**\n   * `avro-1.7.6.jar`
   * `breeze-macros_2.10-0.11.1.jar`
   * `breeze_2.10-0.11.1.jar`"}
```

and turn it into:

```json
data: {"body": "  [Test build #29400 has finished](https://amplab.cs.berkeley.edu/jenkins/job/SparkPullRequestBuilder/29400/consoleFull) for   PR 5266 at commit [`2aa4be0`](https://github.com/apache/spark/commit/2aa4be0e1d7ce052f8c901c6d9462c611c3a920a).\n * This patch **passes all tests**.\n * This patch merges cleanly.\n * This patch adds the following public classes _(experimental)_:\n  * `class IDF extends Estimator[IDFModel] with IDFParams `\n  * `class Normalizer extends UnaryTransformer[Vector, Vector, Normalizer] `\n\n * This patch **adds the following new dependencies:**\n   * `avro-1.7.7.jar`\n   * `breeze-macros_2.10-0.11.2.jar`\n   * `breeze_2.10-0.11.2.jar`\n * This patch **removes the following dependencies:**\n   * `avro-1.7.6.jar`\n   * `breeze-macros_2.10-0.11.1.jar`\n   * `breeze_2.10-0.11.1.jar`"}
```

I've tested this locally and all worked.

/cc srowen pwendell nchammas

Author: Brennon York <brennon.york@capitalone.com>

Closes #5269 from brennonyork/HOTFIX-SPARK-4123 and squashes the following commits:

a441068 [Brennon York] Updated awk to use printf and to manually insert newlines so that the JSON github string when posted is corrected

dev/tests/pr_new_dependencies.sh

@@ -90,8 +90,8 @@ else
     echo " * This patch does not change any dependencies."
   else
     # Pretty print the new dependencies
-    added_deps=$(echo "${DIFF_RESULTS}" | grep "<" | cut -d' ' -f2 | awk '{print "   * \`"$1"\`"}')
-    removed_deps=$(echo "${DIFF_RESULTS}" | grep ">" | cut -d' ' -f2 | awk '{print "   * \`"$1"\`"}')
+    added_deps=$(echo "${DIFF_RESULTS}" | grep "<" | cut -d' ' -f2 | awk '{printf "   * \`"$1"\`\\n"}')
+    removed_deps=$(echo "${DIFF_RESULTS}" | grep ">" | cut -d' ' -f2 | awk '{printf "   * \`"$1"\`\\n"}')
     added_deps_text=" * This patch **adds the following new dependencies:**\n${added_deps}"
     removed_deps_text=" * This patch **removes the following dependencies:**\n${removed_deps}"