`mne[data]` is not a thing anymore

[hoechenberger]

This line:

https://github.com/neuropsychology/NeuroKit/blob/3d004b4777c3e59b288f46b9f0f812ac1e04b5d4/setup.py#L38

can safely be changed to just "mne",, as mne[data] these days only installs mne (the list of "extra dependencies" for data is empty)

https://github.com/mne-tools/mne-python/blob/70fdd8972ffd2dfaaaa9d2a1efa6f0621ec4e61b/setup.py#L63-L66