FIX: Remove test that tests state of warnings before and after assert_warns
TST: Test that the warning registry is empty after assert_warns

Also minor doc change to the statement that this class was
copied from NumPy
FIX warning check in test_affinities
fix to a minor bug with intercept
Merge pull request #3763 from ogrisel/fix-warning-test-affinities

[MRG+1] FIX warning check in test_affinities
TST: Test that assert_warns is reset internally
DOC: Make it explicit that assert_warns clears the warning registry
Merge pull request #3752 from MechCoder/remove_testing_test

[MRG+2] FIX: Modify test that tests state of warnings before and after assert_warns
Merge pull request #3770 from dsullivan7/asgdintercept

[MRG] fix to a minor bug with intercept
Merge branch 'master' into bottou_lr
changing numerical value for buttou due to logic later in algorithm