Add user service to save username, priority, and md5_hash to firebase
Add username input field to registration view
Add User.create in .register before redirecting path to root in auth controller
Link user.js in index.html
Add findByUserName method to User factory and setCurrentUser function
Create event handler for fbsimplelogin to ensure to also call setCurrentUser for logins and refreshes
Delete user from rootScope at logout
add getCurrent and signedIn methods to User factory
Add username & gravatar to navbar, add register and login to navbar
Typo fix, misplaced callback fx outside of function scope
Update post service to add post owner by checking signedIn() user
Update NavCtrl to work with new post promise (which returns postId)
Update post service to delete user's post object when post is removed from Posts
Update posts.html view to  make delete only show if currentUser is the owner and also show who post was submitted by in list
Only show nav add post if user is signed in
Typo fix of post submit redirect