* 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