Adds GithubApi annotated interface for Retrofit.
Wraps the account authenticator in a more appealing abstract class.
Creating an observer that handles the result of a login call

TODO: find proper names for those Better* classes
Extracting a ReactiveAuthenticationActivity
Merge branch 'dev' into adding_authenticator
Using the new ReactiveAuthenticationActivity on the GetherbProject.

TODO: hook this with the RestAdapter to do proper api call
Using the Rest Adapter to trigger the login api call

TODO: Use here clientId and secret from gradle properties.
Merge branch 'dev' into adding_authenticator
HardCoding the path locally for now need to find a proper way to open
project files
Using the resumable subscriber to avoid leaking activity on rotation.
Wrapping the AccountManager inside reactive delegate object
Merge branch 'adding_authenticator' of https://github.com/novoda/gertherb into adding_authenticator
Using the projectDir properties to retreive the credentials
Merge branch 'adding_authenticator' of https://github.com/novoda/gertherb into adding_authenticator
Using handlers inside reactive, ensuring main thread
Merge branch 'dev' into adding_authenticator
Use proper versions & classes
Implementing properly the account manager
Better name for the exception
Good by Novogger