Hi,

it seems that matplotlib by default now pulls dependencies for testing, such as nose and mock. While this might be handy for a matplotlib developer, I think this should not be the default for a matplotlib user.

I think the more canonical behaviour would be to install matplotlib (with its tests even) and then let the user install nose and test if they want to run the tests.

I would be willing to contribute a pull request removing the nose and mock from the list of install requirements.