MRG: Split testing (#4358)
MRG: Split testing (#4358)

* FIX: Split testing

* FIX: Dont use attributes

* FIX?

* FIX: Clearer

* FIX: Fix syntax

* FIX: Remove nonexistent ones

* FIX: Shift the burden

kingjr/mne-python,cjayb/mne-python,drammock/mne-python,pravsripad/mne-python,wmvanvliet/mne-python,Teekuningas/mne-python,wmvanvliet/mne-python,kambysese/mne-python,rkmaddox/mne-python,mne-tools/mne-python,Teekuningas/mne-python,mne-tools/mne-python,pravsripad/mne-python,Teekuningas/mne-python,rkmaddox/mne-python,kingjr/mne-python,Eric89GXL/mne-python,adykstra/mne-python,larsoner/mne-python,larsoner/mne-python,olafhauk/mne-python,drammock/mne-python,larsoner/mne-python,teonlamont/mne-python,jaeilepp/mne-python,pravsripad/mne-python,jaeilepp/mne-python,Eric89GXL/mne-python,wmvanvliet/mne-python,cjayb/mne-python,kingjr/mne-python,olafhauk/mne-python,drammock/mne-python,teonlamont/mne-python,bloyl/mne-python,olafhauk/mne-python,adykstra/mne-python,kambysese/mne-python,bloyl/mne-python,mne-tools/mne-python