run tests/setup in a virtualenv

[michaelheyvaert]

Running make failed on the master branch because pip tried to install a new package globally.

I added some virtualenv commands to install the dependencies locally and run the tests from this environment

[diogobaeder]

So, this build failed because you ran make outside of a virtual environment. Please take a look here: https://provy.readthedocs.org/en/latest/contributing.html

Also, I'm closing this change as it's not necessary, and the build has also failed in Travis.