Warning at `blackify` step

[coderfromhere]

Hi, I'm getting these warnings with an installable renderer:

[13:18:31] WARNING  Black failed to post-process file with an error: Cannot parse: 3:4: The client is provided with async and sync adapters.. Currently  blackify.py:20
                    it happens on non python files, you can safely ignore this message.                                                                                
           WARNING  Black failed to post-process file with an error: Cannot parse: 2:8: include README.rst CHANGES LICENSE. Currently it happens on non  blackify.py:20
                    python files, you can safely ignore this message.         

I think it's relatively easy to recursively filter non *.py files in the folder before feeding the stream to black, but I haven't looked at the post-processor API yet. Not critical though, just FYI to keep track of the things that could be improved.

[asyncee]

Hello, thank you for opening the ticket :) I know about this issue, but can not get my hands on it yet.