Remove unnecessary gitmodules
Virtualenv setup. Fixes $41.
Remove sni_challenge import.
Merge pull request #50 from kuba/remove-sni_challenge-import

Remove sni_challenge import.
Merge pull request #46 from kuba/remove-gitmodules

Remove unnecessary gitmodules
Merge pull request #48 from kuba/virtualenv-setup

Virtualenv setup. Fixes #41.
Get rid of abc
Remove unnecessary executable bits
Clean up imports
Fix undefined-variable
Fix no-self-argument
Fix pylint errors or comment unused invalid code.

augeas_configurator.py: E:220,12: Too many positional arguments for
function call (too-many-function-args)

client.py: E:628,18: Instance of 'Client' has no 'get_cas' member
(no-member)

interactive_challenge.py: E: 35,29: Instance of 'Interactive_Challenge'
has no 'reason' member (no-member)
Clean validator module.
Clean challenge module.
Clean recovery_token_challenge module.
Clean acme module.
Clean CONFIG module, use os.path.
Clean configurator module.
Configurator restart quiet
Clean crypto_util module.