Add hypothesis support to related projects

[rdturnermtl]

The hypothesis-gufunc project recently added hypothesis strategies for generating xarray data structures in version 0.0.5rc2. It should be linked to in the related projects page. It currently uses xarray as a package extra and must be installed as

pip install hypothesis-gufunc[xarray]==0.0.5rc2

The documentation is here.

[dcherian]

Thanks @rdturnermtl , can you send in a PR to add this package?