unit tests grok cleanup

First shot at cleaning up grok out of swarming and opf unit tests (and out of code base) while
maintaining backwards compatability.  Added a tests/integration/py2/nupic/backwards_compatibility
dir with the appropriate unit tests.  May change this to be deeper in the code tree (it is placed
as far up as the code changes were in the tree, which was easiest but maybe not best).  Finally,
I replaced grok with nupic variation of the json schema in tests.