v4.0.0

Breaking Changes

• Wreq exceptions (e.g. non-20x responses from Slack) should no longer propagate outward, thanks to the safe-exceptions library

• Channel type now includes the ID and no longer includes the group vs. private distinction

New and Exciting

• startRTM and friends were added, for retrieving the WebSockets URL

• Much-expanded Tutorial on how to build a real-time messaging bot

• Better Hackage documentation

• Pushes to master now generate documentation, hosted on GitHub Pages