ENH: Return attribute n_iter_ for linear models dependent on the enet solver
TST: Added test to check that warm model converges faster than a cold one
TST: Better to test that warm_start runs only once after the prev model has converged
TST: Added test to check that higher alpha converges faster
Added return_n_iter parameter for enet (and lasso) path
ENH allow y to be a list in GridSearchCV, cross_val_score and train_test_split.
add test for safe_indexing, add another test for cross_val_score
FIX: Fit the data in tests
Merge pull request #3349 from MechCoder/return_niter

[MRG+1] Return attribute n_iter_ for linear models dependent on the enet solver
BUG: Support array interface
Catch ConvergenceWarning in RandomizedL1
ENH improve forest testing + avoid *args
ENH improve rand_int and rand_uniform
ENH rename parameters in MockListClassifiers.
TST non-regression test for CV on text pipelines
Merge pull request #3400 from arjoly/forest-test-oob

ENH improve forest testing + avoid *args
Merge pull request #3396 from amueller/less_loud_randomized_lasso

ENH add convergence_warning option to lars_path.
Merge pull request #3397 from arjoly/tree-factor-rand

Improve random number generator helper in the tree module
Remove deprecated 'mode' parameter from sklearn.manifold.spectral_embedding
Merge pull request #2694 from amueller/allow_y_lists

[MRG+1] allow y to be a list in GridSearchCV, cross_val_score and train_test_split