Add Slack notifications for test builds
Add Slack notifications for test builds

Removed gitter.im webhook for a room that doesn't appear to be in
use.

Travis command line client really wanted to reformat the YAML.

juliandunn/supermarket,nellshamrell/supermarket,tas50/supermarket,tas50/supermarket,chef/supermarket,robbkidd/supermarket,robbkidd/supermarket,robbkidd/supermarket,chef/supermarket,juliandunn/supermarket,nellshamrell/supermarket,nellshamrell/supermarket,robbkidd/supermarket,chef/supermarket,tas50/supermarket,chef/supermarket,juliandunn/supermarket,nellshamrell/supermarket,juliandunn/supermarket,chef/supermarket,tas50/supermarket