This updates the homeshick check command to check for modified files.
Adds tests for modified homeshick test status.

This also moves the 'add a commit' logic in the `check a castle that is
ahead of upstream` test to a function so it can be repeated via DRY
principles.
Merge pull request #88 from squaresurf/check-for-modified-files

This updates the homeshick check command to check for modified files.