Add missing tenant_id to Keystone init

Co-Authored-By: Anderson Mesquita <andersonvom@gmail.com>
Conditionally validate KeystoneAuthV2 credentials

Don't validate the presence of KeystoneAuthV2 credential info if a
keystone client is given.

Co-Authored-By: Anderson Mesquita <andersonvom@gmail.com>
Remove OpenStack log in favor of native logging

Openstack log prevents the client from being loaded due to arg parsing.
Since native logging is used everywhere else, it makes sense to remove
it completely.

All other projects seem to do the same thing as well.

Co-Authored-By: Richard Lee <rblee88@gmail.com>