sklearn version

In [3]: import sklearn

In [4]: sklearn.__version__
Out[4]: '0.19.0'

conda update scikit-learn

conda config --append channels conda-forge
conda install scikit-learn=0.19.2

import nltk
import sklearn

print('The nltk version is {}.'.format(nltk.__version__))
print('The scikit-learn version is {}.'.format(sklearn.__version__))

# The nltk version is 3.0.0.
# The scikit-learn version is 0.15.2.