Introduce Aker authentication.
A gross hack to sidestep SSL verification.

A cleaner way to do this would be to set up a CA and certificates for
our test environment, but that is very much Not Worth It just yet.
Correct a pluralization error.
Auto-configure test environment; verify reachability of CAS servers.

Also update the test procedure described in the README.
Fix up CI procedure.

In particular:

1. We now download the Jasig CAS Server and dependencies separately.
   Download could take a while, but it's not something that Pancakes'
   test runner should treat as a timeout condition.

2. Redirect foreman output to a log.
Use a foreman fork that fixes [1] and works with JRuby.

[1]: https://github.com/ddollar/foreman/issues/330
Adapt NUBIC-specific CI script to start and stop CAS infrastructure.

This commit also bumps up the CAS URL discovery timeout to 120 seconds.
This is pretty long, but I've noticed that some Ruby processes (and
Jetty extraction, etc.) can take quite a while sometimes.  Hopefully two
minutes is long enough.