switch to py.test and pip

[pylons]

switch to py.test and pip

[domenkozar]

Pip has been used since 277d922, now just pytest part is missing.

[stevepiercy]

I've made a new branch for this work. https://github.com/Pylons/pyramid_jinja2/tree/feature-123-pytest

To clarify the scope of this issue, I am working on only documentation and the scaffold. I am not certain whether you want to switch to pytest from nose on the pyramid_jinja2 core package itself, as there was some discussion about this for Pyramid.

[stevepiercy]

@domenkozar I'd appreciate another pair of eyes on the PR #132. I've tested it out by running through the documentation to create a new project from the scaffold, install test dependencies, and run tests, and it works for me, but it would be good to get your feedback.