@ashfurrow => RACify the keypad view

Keypad input sends is a stream man.
The bid view controller subscribes and passes sends the input to a textfield.

RAC Tests well using Dependency Injection, good advice on that. The technique is just changing the RAC stream that fakes the  keypad input triggers so that in tests it's runtimeable. Cool. :+1: 
Nah, that's still part of the runtime bit that unboxes xibs (well, storyboards) and makes connections to actions and outlets. You can just have `sender` as `UIButton`.