Updated dependencies

[leonidpodriz]

Updated from Django 1.7 to Django 3.

This update has been affected it fixed few issues of parent project. (#1 , #2 , #3 )

Try it: https://swapi-new.herokuapp.com/

[Juriy]

Hello @leonidpodriz! Thank you very much for this amazing work. And sincerely apologise for taking so long to respond. This is quite a significant code change and probably deserves a separate branch to test and version it properly.

In the next few days I will review it properly.