split test_common.py into checks and test file.
move dataset generation into estimator_checks
Remove 'DeprecationWarning: using a non-integer number instead of an integer will result in an error in the future' warnings
Closes #2360. Fix tiebreaking.
some cleanups in common_test, speedup.
Make fit_transform and fit().transform() equivalent in nmf
slight speedup
some cleanup
Remove a couple more 'using a non-integer number instead of an integer DeprecationWarning'
Make everything accept lists as input.
Merge pull request #3430 from amueller/test_list_input

[MRG] Test list input
Merge pull request #3433 from lesteve/remove-non-integer-deprecation-warnings

[MRG] Get rid of "DeprecationWarning: using a non-integer number instead of an integer" when running the tests