Code review comment for lp:~ev/charms/xenial/cassandra/snap

I needed to make some more changes, which at at lp:~stub/charms/trusty/cassandra/xenial. The charm is now multi-series, and I'm pushing it to a new home at https://launchpad.net/cassandra-charm ( git+ssh://git.launchpad.net/cassandra-charm ). Further work should land on the git branch (let me know if you have much outstanding work that can't be easily moved in).

There are no integration tests of the snap install yet. Which is fine, as there is no documentation for the new feature either :-) We should fix both of these issues on the git branch.