Apparently I need to (re)start postgresql as well. Got:

$ psql -c "CREATE ROLE rounduptest WITH CREATEDB LOGIN PASSWORD
'rounduptest';" -U postgres
psql: could not connect to server: No such file or directory
	  Is the server running locally and accepting
	  connections on Unix domain socket "/var/run/postgresql/.s.PGSQL.5432"?
The command "psql -c "CREATE ROLE rounduptest WITH CREATEDB LOGIN PASSWORD 'rounduptest';" -U postgres" failed and exited with 2 during .

Author: rouilj

.travis.yml

@@ -49,6 +49,7 @@ before_script:
   - mysql -u root -e 'GRANT ALL ON rounduptest.* TO rounduptest@localhost IDENTIFIED BY "rounduptest";'
 
   # set up postgresql database
+  - sudo service postgresql restart; sleep 30
   - psql -c "CREATE ROLE rounduptest WITH CREATEDB LOGIN PASSWORD 'rounduptest';" -U postgres
 
   # HACK: workaround mysql bug: http://bugs.mysql.com/bug.php?id=74901