Prior to this change, the os_server_action module could not rebuild
servers, because it passed no arguments to the "rebuild" object.
The imageRef parameter is mandatory. If the client does not specify
imageRef, Nova takes no action to rebuild the server.
Change-Id: I0edbdb634feb90d4c54476a4089fcb014c0b83b2
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