Fix Travis, specify PostgreSQL version
Fix Travis, specify PostgreSQL version

jclgoodwin/bustimes.org.uk,jclgoodwin/bustimes.org.uk,stev-0/bustimes.org.uk,stev-0/bustimes.org.uk,jclgoodwin/bustimes.org.uk,stev-0/bustimes.org.uk,jclgoodwin/bustimes.org.uk,stev-0/bustimes.org.uk,stev-0/bustimes.org.uk