The postgres driver blindly creates the migrations table regardless of whether or not it's already been created - this change to the driver first checks the information schema for the existence of the table and does/doesn't create it accordingly
DATABASE_URL can be used to configure any database.
Merge pull request #89 from sgibbons/master

Fix for postgres driver blindly recreating the migrations table
fix minor formatting inconsistency
Merge pull request #90 from pwnall/dburl

Let DATABASE_URL configure any database.
Fix forgotten this binding