* improve link checker
* use ref instead of base_ref
* remove base, always compare to master for modified
* add failing to test
* don't do quiet for testing
* switch error to 404 not 403
* yes to both
* turn off verbose mode
* fix
* actually check things
* fix outstanding link problems
* revet change to run for everything
* use new format
* ignore gitbook failures
* switch back to only running on master
