Configuring git's user.name and user.email for the temporary integration spec repos

Otherwise we would not be able to commit if git is unable to detect user.name or user.email
Seems like we don't need active_support
Being more specific about the expected error message when run outside a git repository
Throwing more descriptive errors
'action' -> 'command'
NoActionsFileFoundError -> NoCommandFileFoundError
Adding commands and specs

Now available:
track, stage, stage_with_patch, unstage, diff, diff_cached, checkout
Bumping version
Fixed missing hashbang in executable
Fixed warning and (re)wrote gem description and summary
Always creating files with random content to disable rename detection
Unstage now supportes staged new files
Bumping version