'Creates and publishes Nightly Build post for the spinnaker.github.io site.
\'Publishing\' in this case means creating a new file, \'git add\'ing it to the
local git repository for spinnaker.github.io, and then pushing a commit
to origin/master.
A private key that has access to --githubio_repo needs added
to a running ssh-agent on the machine this script will run on:
> <copy or rsync the key to the vm>
> eval `ssh-agent`
> ssh-add ~/.ssh/<key with access to github repos>'

def publish_nightly_post(self):

    self.__checkout_githubio_repo()
    self.__read_test_results()
    post = self.__format_nightly_post()
    self.__publish_post(post)
