MAINT: Refactor travis (#6753)
MAINT: Refactor travis (#6753)

* MAINT: Refactor travis

* MAINT: Temporary workaround

* FIX: Better workaround

* FIX: Depth

* FIX: 3.5

* ENH: Try again

* FIX: Again

* Whatever

* FIX: Actually install what we want

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