Ensure that g.v(1).properties serializes via rexpro.
Merge branch '23', remote-tracking branch 'origin'
Integration test modifications for failing tests based on dependencies.

Removed orientdb as an integration test target since there are transactional failures.  Moved jerse-client to a test scope in the pom.  ignored the tree test in rexpro client tests as there seems to be either a bug in gremlin or an unexpected change to how tree is presented (the graph instance itself is in the root of the tree).