Merge pull request #19 from OddBloke/master

Use internal flake8 machinery so that flake8 configuration is picked up correctly
Rename pdb; Graceful flake8 checking.
Merge pull request #20 from alexcouper/pdb_checker

Rename pdb; Graceful flake8 checking.
Delete all captainhook checkers before installing.
Bump to 0.8.1
Correct README.