TODO

2017.08.04:
- Return a possible error result from plugin action
- Integrate chat
    - IRC plugin
    - Slack plugin
    - Generic chat interface for both IRC and Slack
- Command for the GitHub plugin `git remote set origin URL`
- Hello plugin with random display of greetings


2017.08.15:
- Handle Nothing from `matchPlugin message`
- Handle "sorbot: " prefix
- Use `Data.Text` instead of `String`