Add travis deploy support.
Explicitly set python runtime for heroku.
Re-encrypt travis api key.
Re-encrypted for patcon/building.gittip.com repo.
Clone external doc repos manually in before_deploy.
Fix before_deploy commands.
Re-encrypt heroku api key for travis to use gittip org's repo.
Attempt git deploy strategy.
Merge pull request #23 from gittip/23-travis-deploy

Add heroku deploy config stub.