Code review comment for lp:~s-parkinson11/fluidity/sinking_velocity_schema_fix

Thanks Jon,

I have made some changes following your review. Do you think these meet the requirements?

I did notice that all prognostic field advection-diffusion discretisation options checking only happens on scalar fields that are in the root node of a material phase in the schema file. This could do with fixing at some point.

Cheers,

Sam