differentialequations

https://arxiv.org/abs/2012.06684

@samuela is there code to share that could become a tutorial? I think it would be good to make one.

add in docs and in testset a Low-level API example with GPU

CLI already lints, but programmatic interface doesn't lint by default. Model linting should definitely be performed when import fails to avoid having to reimplement validation checks in amici and provide helpful error messages.