Merge pull request #9 from BrandonWilliamsCS/key-response

Added unit tests for new model flow

added correct/incorrect behavior, along with some refactoring

Switched to RX streams for event processing

Some cleanup in the key specs

basic keyboard UI - needs some cleanup and tests

preliminary white key layout

added model unit tests and a little more comments/cleanup

further cleanup and comments

Minimal working example. Cleanup to come.

more Litho and added 'next' button

stepping toward better UI by using Litho components

Converted preliminary flash card to Litho

Preliminary display of random note letter

Basic Android Studio Project