fielddata: fixed tests!

projector: RotTiltProjector now ends in the correct coord system!
diagnostics: Refined the LCurve class (now saves stuff!)
lorentz: Added preliminary Lorentz imaging functions!

1: Rotate arbitrary axis onto the x-axis (with rotation around z)
2: Tilt around this new x-axis (this produces the tilt series)
3: Rotate back around z, so that the x-axis is where it was before!
Assumption: The arbitrary tilt axis lies in x-y!

costfunction: chisq_m/a now track their results (better way?)
diagnostics: added LCurve class (not finished), comments for SVD
fielddata: properly ordered properties, added plot_field for ScalarField
phasemap: fixed bug for symmetric=False, cmap=None (no proper default!)

Added environment.yml and requirement.txt.
GitLab should now produce html coverage artifacts.
io_vectordata: now warns if grid spacing is not equal in all directions.

cmocean, hyperspy to yml file.