Cannot suppress warnings

[trungdong]

I tried to stop the warnings "The target type should be binary" when using the SMOTE method without success.

I believe that the line warnings.simplefilter('always', UserWarning) (added in 23c0b4c) overrides any warning control that I tried and makes sure that the warning is always emited.

I don't think that this behaviour is intended. Could you consider removing those lines from the library?

Many thanks!

[glemaitre]

Those lines will be removed in the refactoring which is coming #290