refs #9865
* This service handles the session store and exporting middleware to be
used for creating and managing sessions
* Updates the auth service index.js file in line with how we do things elsewhere
* After wrapping the exports in a getter, the usage of rewire had broken
the authenticate tests, this commit _removes_ rewire from the tests, calls `init` on
the models before the tests (needed because rewire isn't there) and also
cleans up the use of var.
