test: don't use Django fork for testing

[IlyaFaer]

Closes #485

[IlyaFaer]

@busunkim96, could you take a look and maybe advise something? I saw you dealing with similar problems.

According to the logs requests package is already installed, but somewhy the code can't import it. I've tried to add package update, and even reinstalling it, into several places, but it doesn't give any effect. Seems like something environment related to me.

Thanks in advance!

[busunkim96]

Hi @IlyaFaer,

I would create a new virtual environment and install the test requirements there. It's possible to force an upgrade of the requests version installed in the kokoro environment, but Kokoro may be depending on the specific version installed.

python3 -m venv env
source env/bin/activate
python3 -m pip install -r requirements.txt ...