Protected Attributes -> Strong Parameters

This pull request removes the protected attributes gem from the Gemfile and implements strong parameters for every resource in the project. (in addition to refactoring of many controllers and re-aliasing before filters to before action and other minor style changes)
I'm not sure where this ability comes from... tried to find it elsewhere but no luck. Don't we have to define a [custom action](https://github.com/CanCanCommunity/cancancan/wiki/Custom-Actions)?