Reset axis mappings and instance coordinates

[alerque]

This is my attempt to fix #29 (again), this time from Glyphs.app:

1. Open axis mappings and set all values to 1→1 mappings. Note that on the Glyphs axis graph this ended up with a straight line.
2. Open each instance and set the axis coordinate to the corresponding weight.
3. Set the weight class of the 900 instance to Black (the name already was "Black" but the weight class was "ExtraBold").

@sursly Does this sound sane to you? The result builds fine in current fontship (which under the hood is current fontmake and gftools) and the instances look even to me:

However since I don't understand what problem the uneven axis mappings were supposed to be fixing in the first place I may not actually be qualified to say this is the way to go.

[sursly]

Yeah this is solid. It looks good to me and I think is working fine. I have a preference for interpolation values to not be exactly on the 100s for lighter weights, but I know that is a personal visual thing, not a practical one – especially in a variable font.