Work in progress: Remove view rendering

This is a work in progress. I'm in the process of removing view rendering in favor of simply passing a string to the `text` method. So far I've kept `ActionTexter::Base` a subclass of AbstractController as not to destroy the existing interface too much. Obviously though, this would still be a breaking change since anyone who upgrades will need to move the body of the SMS out of the view and into the controller.

Thoughts?