Change I51105f11565c5ff33b04add36259c8703af11240 moved validate_certs default from None to False.
This causes checks to fail in openstack_cloud_from_module as validate_certs is never None anymore.
This patch changes reverts the default back to None, and reflects this in the documentation.
Task: 41776
Story: 2008600
Change-Id: Ic79510f863cf3a39c3f5c6d99f61d335f92f9388
Collections are new. openstacksdk as of now doesn't support python2.
We shouldn't pretend to support python2 either. If you're using
ansible new enough to use collections, you can use python3.
This release of openstacksdk only supports 3.6 and onwards, so
set that as our min.
Change-Id: I34d544ce48f25bffde8e6e0cf82cdf9a85e681c3