Adds barbican keymgr wrapper

Adds a barbican keymgr wrapper to the key manager interface in
cinder.  This allows barbican to be configured as the key manager
for encryption keys in cinder.  The wrapper translates calls from
the existing key manager interface to python-barbicanclient.

There are two new configuration variables: encryption_auth_url
(the authentication URL for the encryption service) and
encryption_api_url (the api URL for the encryption service).

Change-Id: Ifd0d9b073d7f1c3c92d318c20a080b253008b50c
Implements: blueprint encryption-with-barbican
DocImpact
Provide a quick way to run flake8

"run_tests.sh -p" always checks every file for errors even though you
have probably only changed a handful. This patch adds "run_tests.sh -8"
which only checks the files that were modified in the HEAD commit or
the current working tree.

Copied from Matthew's work in Nova here:
  https://review.openstack.org/#/c/110746/15

Change-Id: I84f6a522da5352a703caa59975643043ec1911fe
Co-Authored-By: Matthew Gilliard <matthew.gilliard@gmail.com>
Merge "Provide a quick way to run flake8"
Merge "Adds barbican keymgr wrapper"