[Laravel4] Fixed Cest testing when using Laravel's Auth

First of all, I reverted 3bc9f06 for issue #1205.Initialization it's only done on the _initialize() method, the actual workaround wasn't working for Cest classes.

Now, after each scenario, we will logout the user, flush cache and session. It's not the cleanest way yet, but it does works with Cest and Cept functional tests.

To confirm that this won't break Cept testing, I've pulled [LimeBlast/larabook](https://github.com/LimeBlast/larabook), the @laracasts series where, probably, @JeffreyWay reported the bug on users who weren't logged out on each test.

This is still messy, I've tried different things and this was the only way of getting both types of testing working as expected. I'll continue exploring better options.