Add mypy (#4386)

* Initial configuration of mypy in box, correction of base mypy errors.

* Move mypy install to toe

* Add pylint comments for typing imports.

* Remove typing module for Python 2.6 compatibility.

certbot/reporter.py

@@ -7,7 +7,7 @@ import os
 import sys
 import textwrap
 
-from six.moves import queue  # pylint: disable=import-error
+from six.moves import queue  # type: ignore  # pylint: disable=import-error
 import zope.interface
 
 from certbot import interfaces