Display the url

libpq 9.2 can parse this, so we should start returning it.
heroku run:detached --tail

Tails the logs of the run processes.

Restructured the log display logic into a helper class.

Inspired by a convo with @csquared and (maybe) others.
Merge pull request #701 from freeformz/db_url

Display the Databases URL
Merge pull request #685 from freeformz/run_detached_tail

heroku run:detached --tail