ansible/ansible — pull request #8829 by quiver (2014-08-31 13:29:40+00:00)
Title: Add slack callback plugin

This is a callback plugin to post messages to Slack(https://slack.com/)

Due to service similarities, most codes are copied from `plugins/callbacks/hipchat.py` and my addition
modification is API handling.

As commented in the code, two environment variables(`SLACK_TOKEN` and `SLACK_DOMAIN`) are required.