Tests can now be run cleanly.

They clean up after themselves properly and set themselves up, so they
no longer depend on running them all together.

To support this, added a `shutdown()` function on the main Reflip
object, which in turn calls `close()` on its storage adapters. For the
file storage, this means stopping its file watcher. For the redis
storage, it means closing its client & stopping any refresh timers.

For a bonus, updated package dependencies.

Bumped version in prep for release.