Fit-Check added to NiftiLabelsMasker
changed exception type + unit tests pass now
Fix typo in error message
fit-check for Nifti([Labels, Maps])Masker + type in BaseMasker corrected
de-sniggle-ized
Merge pull request #267 from banilo/masktransf

[ENH] Fit-Check added to NiftiLabelsMasker
Added generator for niftis