Update Cypher test dependencies

o ScalaTest_2.10 2.0 has been released
o Add ScalaUtils_2.10 2.0 (=== operator now lives in separate artifact)
o Add ScalaCheck_2.10 1.11.0 (we want to work with it)
Add GraphDatabaseService.mergeByConstraint (Core API version of merge)

o Provides a utility for adding unique entries for a constraint (getOrCreate) with proper locking, i.e.
  transactions using mergeByConstraint block each other
o Add Merger interface and MergeResult class to core API
o Update documentation examples for creating unique nodes
o Add UniqueFactory.asMerger to integrate existing API (UniqueFactory may be deprecated in the long term)