Improved filtering and fixing of source code generated from the grammar. This version found a novel bug: `"pass \\r\\n"` is accepted by the built-in `compile()` and `exec()` functions, but not by `black` or `lib2to3`.
0.0.1
Initial release. This is a minimal proof of concept, generating from the grammar and rejecting it if we get errors from `black` or `tokenize`. Cool, but while promising not very useful at this stage.