Issues with importing StabilitySelection

[trislett]

Hi,

I'm sure there's a better way to do this, but I had to change these two lines in order to import StabilitySelection from the latest version.

stability_selection.py, line 26

from joblib import Parallel, delayed

random_lasso.py, line 21
from sklearn.linear_model._base import _preprocess_data

Thanks for building this module!