Initial fix.
Fix pyflakes errors.
Add custom pyflaks runner.
Merge branch 'master' into 66-diff
Merge branch 'master' into 67-pyflakes-clean
Update travis to run twistedchecker.
Check twistedchecker with pyflakes.
Update pip to pin versions from install_requires
Merge pull request #74 from chevah/67-pyflakes-clean

Clean code of pyflakes warnings
Revert verstion.
Merge master.
Merge pull request #70 from chevah/66-diff

Fix --diff option