Revert "fix Travis PostGIS installation?"
Revert "fix Travis PostGIS installation?"

This reverts commit a7180f55a21861b3e6c055c85e2089370e53be1e.

jclgoodwin/bustimes.org.uk,jclgoodwin/bustimes.org.uk,jclgoodwin/bustimes.org.uk,jclgoodwin/bustimes.org.uk