Remove recommendation of using unmaintained nose
Remove recommendation of using unmaintained nose

The nose project has ceased development. The last commit is from Mar 3,
2016. From their docs page:

https://nose.readthedocs.io/

> Note to Users
>
> Nose has been in maintenance mode for the past several years and will
> likely cease without a new person/team to take over maintainership.
> New projects should consider using Nose2, py.test, or just plain
> unittest/unittest2.

PythonCharmers/python-future,PythonCharmers/python-future