Cleint charm to excercise the keystone credentials interface:
https://github.com/openstack/charm-interface-keystone-credentials/
Creds-client relates to keystone via the keystone-credentials interface.
# Build the charm
cd creds-client
charm build -s $SERIES
cd $SERIES/creds-client
# Deploy the charm
juju deploy .
juju deploy keystone
juju deploy percona-cluster
juju add-relation creds-client keystone