Send message on slack channel #rankme when a game is saved
Add signals 'game_played' and 'team_ranking_changed'
Add slack module
Don't crash when announcing a game with a not-yet-ranked team
Add dummy slack api token in test env
Use env SLACK_API_TOKEN in settings
update readme
Define token in base.py instead of local.py
fix test
Merge remote-tracking branch 'origin/master' into slackbot

Conflicts:
	game/models.py
	game/signals.py
	rankme/settings/base.py
Add tests for signals
Put signals tests in their own test case
Add tests for the slackbot
Make sure all tests use the mocked slack module
Use assertEqual instead of assertEquals
Add competition information to slack messages
Fix tests
Merge remote-tracking branch 'origin/slackbot'