changed db connect string to use environment variable (per Heroku guide)
more tweaks to get postgres to work on heroku
Even more tweaking to get Heroku postgresl to work
(I believe the root cause is how to reference ${DATABAE_URL} in application.conf)
Set application of Evolutions to true
(in the future we need to figure out a way to explicitly run evolutions instead of trusting that the data is volatile…but for this stage of dev, who cares?)