[SPARK-10682][GraphX] Remove Bagel test suites.

[rxin]

Bagel has been deprecated and we haven't done any changes to it. There is no need to run those tests.

This should speed up tests by 1 min.

[SparkQA]

Test build #42629 has finished for PR 8807 at commit 88ac464.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds the following public classes (experimental):
  • class Interaction(override val uid: String) extends Transformer

[srowen]

Belatedly, LGTM. Could just disable them too but this seems fine as well.