Fix code reference to older version of flake8 (#426)
Fix code reference to older version of flake8 (#426)

The pre-commit module contained a reference to the variable
DEFAULT_CONFIG which does not exist in the version of flake8 packaged
with the project. The DEFAULT_CONFIG defines the path to the current
user's local flake8 config file.

The flake8 2.6.2 version packaged with project has been refactored to
set the local flake8 config file in the flake8/main.py module.
Netflix/lemur,kevgliss/lemur,kevgliss/lemur,Netflix/lemur,Netflix/lemur,nevins-b/lemur,Netflix/lemur,kevgliss/lemur,nevins-b/lemur,nevins-b/lemur