Add Django 2.1.5 and latest support.

[DaniilSezonov]

Close issue #286.

[gtnx]

Looks good.
@jrief I see that last merged PR was almost one year ago. Have you considered integrating other maintainers?

[jrief]

Have you considered integrating other maintainers?

Yes, but noone asked until now. Would you like to become one?

[gtnx]

Yes.
I use this package in production in my company for almost 4 years now. I'm not super familiar with this package codebase but i can totally support you on those kind of tickets which are important for the community.

[gtnx]

@DaniilSezonov Could you add the 2.1.5 to the ci matrix. IT's in travis.yml in the env section?
Thanks

[jrief]

btw., what's your username on PyPI?

[DaniilSezonov]

Something was wrong, sorry, I have no experience with CI/CD configuration.

[DaniilSezonov]

Trying again

[gtnx]

@jrief this is guillaume.thomas

[gtnx]

As i said it looks good. I tested it using a personal project and not the example project which still needs to be compatible with latest django versions (See #246).

[gtnx]

@jrief Could you add me as well on pypi? Thanks