Record application deployments to Statsd

Every time a Deployment object is created for a particular application, register
that deployment by incrementing a statsd counter for that application.
Be stricter about what we accept for repo

Since shortname now defaults to the second half of the slash-delimited "repo"
field, we should probably be a little stricter about what we accept in this
field. Add a simple regex validator that enforces that repo is in the form:

    <anything but whitespace or a slash>/<anything but whitespace or a slash>
Add shortnames to db/seed.rb for apps that need them