Update Readme

wip
Move open method to Repo
Refacor: mv setup to gogit; functions as methods

 - Moved the github client code to the entry point (gogit.Run file)
 - Created Pull struct (Data, State, Repo)
 - Added Update function as metod on Pull
 - Pull.Update fetches the full detais of the pull and sets the State
extract OpenPulls into repo.go
Concurrency: Pull updates

This speeds things up!