Extensible?

A general question to ask -

The idea is very nice. And I touched this repo 3 months back. I am having a relook. And probably recollecting the things here?

The project is very nice but if I am not wrong there is no way I can add my own middleware in middleware directory like for example

```
from toolz import merge
from ..formation import _REQ_HTTP

def auth(auth_key=None, access_token=None, content_type='application/json'):
def auth_middleware(ctx, call):
req = ctx.get(_REQ_HTTP)
req.headers = merge(req.headers, {
'auth_key': auth_key,
'access_token': access_token,
'content-type': content_type
})
return call(ctx)

return auth_middleware
```

And then changing the below file too like

> formation/middleware/__init__.py

` from .auth import auth # noqa`

So far so good but then I will have bump up the version

> formation/__version__.py

OR raise a PR.

This method / process doesn't seem a lot extensible. Is the extensibility thing missing? Or is there workaround on the release thing? Can I fork and and release it some other name ****/formation-**clone** with your @jondot permission of course. I am asking permission here.

May be a newbie question or I misunderstood something.
I want to release a bit of functionality. like the auth above and playing with https://pypi.org/project/py-zipkin/ integration. Have 2 -3 ideas in mind, really want to explore.
Will that be ok?

Or need your guidance (sorry for newbie question)