Closes #35. Add more options for Python PEP8 beautifying.

Options:
- max line length
- indent size
- ignore (errors)

- [x] Also fixed [typo](https://github.com/donaldpipowitch/atom-beautify/commit/88651447a721f73fb58ae076b04ae296f0b4318b#commitcomment-6830459) causing very important bug, such that languages were not loaded correctly and options were missing.