Added tests, kinds now as tuple
Don't display warning during tests
Make user specify origin_head
Merged 3D to 2D mapping of electrode positions

There was a duplication of code for mapping 3D electrode positions
to a 2D space. Both the `_auto_topomap_coords` and
`make_eeg_layout` functions had their own implementation.
updated docstrings
Implement option 2

Raise warning when no digitization points are present
and no origin_head is specified.

Add origin_head parameter to topomaps.
Add separate testcase for _auto_topomap_coords