Update documentation to reflect change in Gunicorn 20

[bilalshaikh42]

Gunicorn 20.0.0 no longer supports the factory pattern.
A simple change to the documentation will prevent users from trying this method

Here is the github issue regarding the change:
benoitc/gunicorn#2159

[ThiefMaster]

you shouldn't have an app instance there, I'd rather use myproject.wsgi:app instead.

[ThiefMaster]

also, I'd rather see gunicorn add explicit support for calling an app factory.

[bilalshaikh42]

also, I'd rather see gunicorn add explicit support for calling an app factory.

I agree with this, but it seems as if the plan is to deprecate this feature.

[bilalshaikh42]

you shouldn't have an app instance there, I'd rather use myproject.wsgi:app instead.

I can't get this pattern to work on my project. Setting a variable to equal the return of the app factory is working. How does the "wsgi" call fit in here?

[ThiefMaster]

you add a wsgi.py that imports and calls your app factory

[tilgovi]

I agree with the suggestions. Having a separate module that calls the factory and exposes the result is a good way to do this.

[tilgovi]

Looks good to me.

[davidism]

Given that benoitc/gunicorn#2178 is slated for 20.0.1 and adds this functionality back, I'm going to close this. Thanks for working on it.