Reformat after rendering

[mcflugen]

This pull request cleans up the code somewhat but mainly changes the babelize command to automatically run both black and isort (programmatically) on the rendered Python output.

I ended up sneaking some other stuff into the pull request.

• git init is run when a new project is created
• run versioneer programmatically
• added subcommands to the babelize command
  • babelize init: creates a new project that babelizes a library
  • babelize update: updates an existing babelized project
  • quickstart: creates babel.yaml (formally plugin.yaml) configuration files
• only support Python 3.8 (because, why not?). The generated babelized project will be compatible with Python 3.6+
• drop Python 2.7 support of the babelized project
• metatdata for the babelized libraries is installed along with the package (inside the package's data folder) rather than under share/csdms