ENH remove _is_1d and _check_1d_array thanks to @GaelVaroquaux
flake8
ENH raise ValueError with row vector if multilabel or multioutput is not supported
ENH being less permissive thanks to @jnothman
FIX TST with multilabel helpers
Revert definition of is_indicator_matrix
ENH handle properly row vector
Remove redundant code
ENH check_arrays once
flake8
TST helper function
COSMIT