DOC: Improvements to children_ attribute in AgglomerativeClustering
Borrow a bit from scipy definition
ENH: Return distances option for linkage_trees
Merge return_distance tests of both linkage and ward tree
Add documentation for return_distances option
Small typo fix in the comments: "whther" --> "whether"
Merge pull request #3989 from hammer/patch-2

[DOC] Small typo fix in the comments: "whther" --> "whether"
Merge pull request #3976 from MechCoder/agglomerative_playground2

[MRG] DOC: Minor Improvement to `children_ attribute` in AgglomerativeClustering
TST: Test ground truth in linkage trees
MAINT remove deprecated auc_score function
Merge pull request #3985 from MechCoder/return_distances

[MRG] ENH: Return distances option for linkage_trees
COSMIT flat > nested / avoid duplicate validation

Also, PEP8
TEST A duplicate minimum value should not yield non-finite predictions in IsotonicRegression
FIX Adding eps to minimum value in clipping in IsotonicRegression
Fix typo in SVM docstrings
Merge pull request #3997 from pricingassistant/doc-typo-fix

Fix typo in SVM docstrings
STY remove unnecessary variable/operation
ENH sparse metric support for paired distances
DOC Add inline comment with reference to scipy issue
Merge pull request #3995 from jmetzen/fix_isotonic

[MRG] FIX Isotonic Regression for duplicate minimal value