Limit to two players using Firebase's 'loaded' event

Closes #37
Merge branch 'limit-to-2-players'
Basic game view
Show each sentence on its own line
Pass sentences between the user

On enter, submit the sentence.

Clear the sentence after submitting.
Make panel for words to use
Merge branch 'make-game-view'

This closes #1, the Refresh bug
Merge pull request #38 from wlaurance/master

Basic Game Play