Fix travis builds

[svandragt]

+mysqladmin create wordpress_test --user=root --password= --host=localhost --protocol=tcp
253mysqladmin: [Warning] Using a password on the command line interface can be insecure.
254�mysqladmin: connect to server at 'localhost' failed
255error: 'Can't connect to MySQL server on 'localhost' (111)'
256Check that mysqld is running on localhost and that the port is 3306.
257You can check this by doing 'telnet localhost 3306'
258The command "bash bin/install-wp-tests.sh wordpress_test root '' localhost $WP_VERSION" failed and exited with 1 during .

looks like there's no database.