Now that there is a passing gate job, we can claim support for
Python 3.5 in the classifier. This patch also adds the
convenience py35 venv.
Change-Id: I87c806ee2219f42972e5bfef23f3a6504a38aaf0
Remove old and unused constraints environments from tox.ini. Those
have never been used. Use standard environments as default list.
Note that the repo has in the past not used constraints in OpenStack
CI, this change keeps the status quo.
For more information about constraints see:
http://lists.openstack.org/pipermail/openstack-dev/2016-August/101474.html
Change-Id: Icf74abe8ff90f06fe8c9c6a7e1f3a8bd1bdce3fd