We're being too strict - there is a third possibility, which is that a
user will have defined the OS_* environment variables and expect them to
pass through.
The rest of ansible uses validate_certs, so make that the main
documented parameter. However, leave verify as an alias since that's the
passthrough value to the underlying libraries.
There is an old PR that shows a great use case for having a different
set of states for the server module. Before the other modules start
being in real use, pull this out so that we don't get ourselves into a
pickle.