Alpha Release 4

• Support for a schedule task to handle checking foreign PRs:

  name: Spell checking
  on:
    schedule:
      # * is a special character in YAML so you have to quote this string
      - cron: '0 * * * *'
  

  The initial version only looks at one hour's worth of PRs. I'll eventually support a configurable time window. I may need to teach it how to recognize if it's already checked a given commit (in case the cron runs, e.g. every 5 minutes and the window is an hour).