Code review comment for lp:~nskaggs/juju-release-tools/add-daily-build

I made a new template string. Feel free to comment on things like we really need -ubuntu in there, etc.

I also added tests -- anything else you'd like to see specific to daily?

In addition, I did a test run using this new code with the existing job to ensure I didn't break anything: http://juju-ci.vapour.ws/view/Release, package, publish/job/release-juju-create-source-packages-test/1/