OAK-1118: Removing and readding mix:versionable fails if node is referenceable
- do not use testRootNode for test but rather create a child node and perform test there. this avoids side effects with other tests.
- @Test, @Before and @After annotation are redundant because these are old school JUnit tests

git-svn-id: https://svn.apache.org/repos/asf/jackrabbit/oak/trunk@1550452 13f79535-47bb-0310-9956-ffa450edef68