Direct import of auth plugin 'keystone.auth.plugins.password.Password' is deprecated

[Peter Matulis]

This deprecation warning was found in keystone.log:

(stevedore.named): 2019-07-17 22:30:08,552 WARNING Could not load keystone.auth.plugins.password.Password
(keystone.auth.core): 2019-07-17 22:30:08,553 WARNING Deprecated: Direct import of auth plugin 'keystone.auth.plugins.password.Password' is deprecated as of Liberty in favor of its entrypoint from 'keystone.auth.password' and may be removed in N.

Setup:

Bionic
OpenStack Queens
Juju 2.6.5
LXD containers [1]

LXD host:
Linux node-pytheas 4.15.0-54-generic #58-Ubuntu SMP Mon Jun 24 10:55:24 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

[1]: https://github.com/openstack-charmers/openstack-on-lxd