Setup github oauth
Add UISearchBar to ReposVC
Add api call for github repos with search params on searchBarSearchButtonClicked
Add check to determine if session already authenticated or if access token already stored so that oauth request only happens once
Add UI for RepoCell nib
Implement repo search based on user search params
Add date extension for validating search bar input; add NSDate extension for display an NSDate as a string with a given format
Add UsersVC
Add UserSearchVC and refactor GithubService
Implement user class; change repo owner to be of type User; implement user collection view
Add UserVC to display single user
Implement custom animation when transitioning from UserSearchVC to UserVC
Move NavController delegate setting to prevent retain cycle