Colored diff output

[friedkeenan]

As is, to get colored diff output, one needs to use an external tool like colordiff to color the diff for readability, however this also seems to complicate the "checking" feature of returning an error code if changes are needed. It would be convenient and useful to be able to just pass an argument to autoflake for whether or not to color the diff output.

Unfortunately, difflib does not seem to have a way to get colored output, but I did find this gist which could possibly be helpful (particularly the comments).