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
Added feature to fix #1523
ENH decision_function now returns #votes and scaled scores.
TST Added test to assertain correlation of decision function and prediction
FIX Implemented _check_is_fitted for OvO similar to the one for OvR
FIX Correct and separate the scaling logic for scores
TST Add decision_function tests to check for votes/scores

ovo_ties test will use decision function to calculate votes and score.
COSMIT Undo aggressive pep8
ENH use the decision_function to compute the prediction