orbit integration test with EllipticalDiskPotential
some tests of the Jacobi integral, incl. that for DehnenBarPotential
correct shape of L in Jacobi
For RZOrbit's Jacobi, assume the pattern is in the plane (it has to be for RZ to make sense)
don't cover not being able to load the orbit integration library
further tests of Jacobi
add further mock non-axisymmetric potentials to integrate orbits in