Merge lp:~bjornt/charms/xenial/glance-simplestreams-sync/no-python2 [r=ack,sparkiegeek]
Allow the charm to work on xenial.
Xenial doesn't have python2 installed by default, so it needs to be
installed before the real install hook gets executed.
The pattern used is the same as for other openstack charms. The install
script was copied from the glance charm.