Fix error handling when outside git repos
Add instructions for Homebrew users.
Merge pull request #44 from kudos/homebrew

Add instructions for Homebrew users.
Add instructions for Homebrew users.
Final touch on kudos' outside repo error fix (improves readability)
Merge branch 'kudos-no-repo-error'
Move echo_green & echo_red functions to above exit_with_error to fix command not found error
Add permission-denied troubleshooting to README
Fix typo in wlmeng11's README changes