[scikit-learn] Preparing a scikit-learn 0.18.2 bugfix release

[Olivier Grisel]

In retrospect, making a small 0.19 release is probably a good idea.

I would like to get
https://github.com/scikit-learn/scikit-learn/pull/8002 in before
cutting the 0.19.X branch.

-- 
Olivier Grisel