v0.3.2 - Reproducible example notebook with Zenodo datasets

• Separate testing and docs environments
• Fix MOM6.yaml file so that collect_budgets gets horizontal
  mass convergence from the mass convergence diagnostic as opposed
  to the difference of the horizontal mass fluxes. In native coordinates,
  this makes no difference. In density coordinates, however, the two
  give different answers because they are binned using different density
  fields.

Full Changelog: v0.3.1...v0.3.2