* Removes future from python-exp v3 sample
* Removes future from python-exp v2 sample
* Deletes future from remaining python-exp files
* Removes six from python-exp templates
* Removes six from python-exp samples
* Removes mock from python-exp
* Python-exp switched to py3
* Removes python 2.7 for python-exp ci testing
* Requires python>=3.3 for python-exp
* Reverts unnecessary changes to two templates
* Adds oneOf + anyOf schemas, models and tests to python-experimental
* Adds setUpClass and tearDownClass
* Removes newline in method_init_shared.mustache
* Regenerated v3 spec sample for python-experimental
* Fxes test for discard_unknown_keys
* Moves new models into existing spec, regen python-exp and go-exp
* Also fix python-exp windows file