Fix Rails 4.1 test errs by not re-including Authlogic in test classes

### WHAT

Fixing the Rails 4.1 test errors. This is really a bug that affects all Rails versions' tests, but just surfacing in 4.1.

### WHY

There are a few places in the tests where `acts_as_authentic` is called on the `User` test model.

Whenever `acts_as_authentic` executes, it includes all of its modules into the receiver (eg the `Authlogic::ActsAsAuthentic::Login` module, which adds validations).

Hence, when you run the full test suite, there are a bunch of duplicate validators on the `User` class.

### ALTERNATE

Another fix would be to just ensure the modules can't be included multiple times, but maybe that's not necessary until someone runs into it in a non-test environment?