Upload builds to PyPI and conda

[dougiesquire]

We should upload builds to PyPI and conda to facilitate use in other projects. Builds should be tested in CI and build+upload should be done as part of a proper release process. See Payu for an example.

[anton-seaice]

We could consider including test 'artifacts' with the release. This would cover the percentage of tests passing, but also the dependencies used (in case there is some issue in the future caused by changing dependencies).