Make v2 and v3 identity apis configurable

This commit adds a config option to the identity feature enabled group
to specify whether the v2 and/or v3 apis are enabled in keystone. In
the process of adding this feature the logical split between v2 and v3
tests in the identity api tests is made more clear. Additionally as part,
of the split several bugs are fixed where the v2 api was being called
in the v3 tests.

Change-Id: I0d727f3567c82fe512b956110bb813119ced0b3d
Support building wheels (PEP-427)

Universal is used to identify pure-Python module(by bdist_wheel). For
these, it is sufficient to build a wheel with _any_ Python ABI version
and publish that to PyPI (by whatever means).

Change-Id: Ib15e61ce3edf6f2694795167c85d40457bf11292
Merge "Make v2 and v3 identity apis configurable"
Merge "Support building wheels (PEP-427)"