Pre-push hook prevents from pushing to fork of DGP repository.

[nehalmamgain]

The pre-push hook prevents from pushing to fork of DGP repository with the following error message.

Here, the virtual environment was created and activated by following this doc.

(dev) nehal@device:~/dgp$ git push nehaldgp feat/nehal/point-line-polygon-3d-proto
************* Module .pylintrc
.pylintrc:1: [E0015(unrecognized-option), ] Unrecognized option found: accept-no-param-doc, accept-no-return-doc, accept-no-yields-doc
Aborting push due to files with lint.
error: failed to push some refs to 'git@github.com:nehalmamgain/dgp.git'

[nehalmamgain]

Also make test fails with the following message

pytest -v /home/nehal/dgp/tests/
/bin/sh: 1: pytest: not found
make: *** [Makefile:72: test] Error 127

pytest should also be added to the installation instructions for the virtual environment.

[nehalmamgain]

Pre-push issue solved by #109.
Make test issue remains. Will open a PR for that.

[nehalmamgain]

Virtual environment fixed by #110.