Adding more Heroku images.
Merge remote-tracking branch 'origin/source' into source

* origin/source:
  Fixing a typo
  Modifying the dev/test guide for billing changes
  Adding Ruby Quickstart
  Updating spacing on the node quickstart.
  Updating the python quickstart to reflect new billing changes.
  Adding space.
  Fixing the REST / PHP / NODE quickstart for billing