Adding heading
Adding section on contributing
Adding section on licence
Adding CONTRIBUTING.md
Remiving references to message_handler
Link to contributing.md in readme
add Pwwka the bunny bus, based on the Cat But from My Neighbor Totoro (of course)
Don't need to specify git source
Merge branch 'readme_updates_uhy' of github.com:stitchfix/pwwka into readme_updates_uhy
cleanups and reformatting

Also differentiating testing the use of this gem vs. testing the gem itself.
Merge remote-tracking branch 'origin/master' into readme_updates_uhy

Conflicts:
	README.md
Merge pull request #3 from stitchfix/readme_updates_uhy

Readme updates