Feature delete branch from other branch

Ok, so there were 5 cases identified that needed to be taken care of when issuing ``git [feature|hotfix] finish [name]``:

`` current branch -> branch to delete ``
`` a -> b `` --- delete b and stay on a
`` b -> b ``--- checkout master and delete b
``master -> b `` --- delete b and stay on master
`` a -> <no name> `` --- checkout master and delete a
`` master -> <no name> `` --- error

Edge cases were:
  1. If the user provided the same branch name as the one he was currently on
  2. If the user didn't provide any name while he was on master