Terms for SphericalGrid1D not implemented

[mhvwerts]

This is not very urgent. I am trying out PyFVTool and it seems that the 1D spherical mesh has not been implemented yet.

I was trying to port the example concerning 1D spherical diffusion from the original Matlab FVTool to PyFVTool, and found that the createMeshSpherical1D does not exist (yet).

For now, I will go play in a different coordinate system. Anyway, thanks for PyFVTool which is an interesting option for using the finite-volume method in teaching transport phenomena and for setting up toy(?) models for research.