WIP - initial work to support django 2.0

[auvipy]

work in progress. initial attempt to support dj v2. some more failures will be fixed after the release one by one

[auvipy]

im quite not sure about the proper fixes for the failures in 2.x version. could you suggest some light

[auvipy]

seems like some pytest related issues need to be addressed

[carltongibson]

@auvipy Thanks for this. I'll give it a proper look anon. 👍

[xordoquy]

I'll be fine if we already get the "infrastructure" part into master - i.e. up to the updated tox.
Should be fine since failure is allowed on the 2.0 build.

[carltongibson]

@auvipy as per @xordoquy's comment, if you can split this into two I'll merge the first part today.

1. Update tox/travis etc.
2. Fixes for 2.0 compat (eventually making pass required...)

For 1. can you please Drop 1.8 as per #5058 (comment).

This will require a 3:

• Clean-up 1.8 compat

... but I'd like to take that separately.

(Please rebase. Thanks!)

Thank you for the effort!

[gcbirzan]

Btw, aside the changing of names, the other thing needed is a way to get the URL pattern from the new object. Initially, it was urlpattern.regex.pattern, it should now be urlpattern.pattern.regex.pattern. I guess a helper in compat could do this, this is where the old way is used: https://github.com/encode/django-rest-framework/search?utf8=%E2%9C%93&q=%22regex.pattern%22&type=

[carltongibson]

Closing in favour of #5457. @auvipy Thanks for the effort!