isort is a Python utility to to sort imports alphabetically,
and automatically separated into sections.
This config matches the Django coding style:
https://docs.djangoproject.com/en/dev/internals/contributing/writing-code/coding-style/#imports
```
Put imports in these groups: future, standard library, third-party libraries,
other Django components, local Django component, try/excepts.
```
This also adds a tox target, not yet executed by default,
which can be used to easily apply isort (`tox -e isort -- --apply`)
