Making pytest the standard test suite (instead of nose)

[Thomas De Schampheleire]

Hi,

I've been using pytest for a while now, and think we should consider
making it the default test suite instead of nose.

As I see it, there are following points to do:

1. silence the database setup code by default. Currently, the initial
step of the tests sets up the database and all commands are passing by
on the terminal. This should be silent, just like with nose.
However, I don't know how to fix this correctly, and I hope Marc,
Ronny or Brianna could help here.

2. once point 1. is solved, add pytest and pytest-sugar in setup.py dependencies

3. update documentation


Thoughts?

Thanks,
Thomas