Relativistic magnetic interactions from non-orthogonal basis sets

More on the theoretical background can be seen on arXiv.

TODO

• get automatic emax

• move tests to src

• better readme

• dependency on how we choose the perpendicular directions

• Use ReadThe Docs addons

• Document

• warning for insulators about the fermi level positioning

• magnopy out lx ly lz?

• add mesh and converge to batch