FIX: ENetCV and LassoCV now accept np.float32 input
Merge pull request #3178 from MechCoder/Iss3174

[MRG+1] ENetCV and LassoCV now accept np.float32 input
TST Refactor test of sklearn/ensemble/tests/test_forest.py
TST refactor oob score testing
Merge pull request #3182 from arjoly/test-forest

[MRG] Modernizes tests for the forest module