Installation requires nose

[ColCarroll]

Importing certain modules requires nose (stack attached at bottom). Two possible solutions:

1. add nose to the install_requires in setup.py (it looks like you might also want to add the rest of requirements.txt there? Or perhaps you are leaving them all out on purpose?)
2. Use a bit of a hack in permutation.py:

try:
    from nose.tools import nottest
except ImportError:
    def nottest(f):
        return f

Let me know if either of these would be helpful and I would be happy to submit a patch!

>>> from mlxtend import evaluate

---------------------------------------------------------------------------
ModuleNotFoundError                       Traceback (most recent call last)
<ipython-input-125-94b63739480a> in <module>()
----> 1 from mlxtend import evaluate

~/anaconda3/envs/gates_labels3.6/lib/python3.6/site-packages/mlxtend/evaluate/__init__.py in <module>()
     13 from .bootstrap_outofbag import BootstrapOutOfBag
     14 from .bootstrap_point632 import bootstrap_point632_score
---> 15 from .permutation import permutation_test
     16 
     17 

~/anaconda3/envs/gates_labels3.6/lib/python3.6/site-packages/mlxtend/evaluate/permutation.py in <module>()
     10 from itertools import combinations
     11 from math import factorial
---> 12 from nose.tools import nottest
     13 
     14 

ModuleNotFoundError: No module named 'nose'

[rasbt]

Good point, we should definitely do something about that. While I try to avoid "hacky" workarounds, I would actually favor your second suggestion because nose is not required for the function itself but the nottest is more required as a consequence of nose itself.

Let me know if either of these would be helpful and I would be happy to submit a patch!

If you could submit a patch, that'd be great! Thanks!

requirements.txt there? Or perhaps you are leaving them all out on purpose?

Hm, I think the requirements file got a bit stale/abandoned over time and could def. use an update :P