Fix several deprecation warnings

database_user -> mysql_user
mysql_module removal
sql_connection -> database_connection

Needs: https://github.com/redhat-openstack/openstack-puppet-modules/pull/132
Change-Id: Ia7e22b0d809e40e64dc664f281f7274a4102751c
Signed-off-by: Gael Chamoulaud <gchamoul@redhat.com>
Merge "Fix several deprecation warnings"