Enforce n_folds >= 2 for k-fold cross-validation
COSMIT much simpler agglomeration inverse_transform
TST stronger test for agglomeration transforms
Merge pull request #2075 from jnothman/agglomeration_simplify

COSMIT much simpler agglomeration inverse_transform
FIX : use unique from fixes
enhanced (hopefully) DBScan documentation; killed some whitespace along the way...
Merge remote-tracking branch 'upstream/master' into dbscan-doc-enh
DOC minor fixes to Ward docstrings
DOC fix docstrings for AgglomerationTransform
DOC detail Ward.children_ and fix n_components_ type
DOC comment on Ward algorithm
DOC clean pooling_func arg type
Merge pull request #2074 from jnothman/ward_docstring

DOC minor fixes to Ward docstrings
DOC no more mention of the Bunch in the narrative docs
DOC copy comment describing hierarchical clustering children
Merge pull request #2076 from pprett/dbscan-doc-enh

MRG: Dbscan doc enh
FIX don't rely on Bunch behavior with fetch_covtype

For consistency with new documentation
(176c9cee0805adfd61891e192ae47a55a8628a5f).

Still returns Bunch so as not to break third-party scripts.
DOC much more readable formula in chi2 kernel doc
Remove invalid todo comment
Merge pull request #2080 from ahojnnes/dist-todo

Remove invalid todo comment