Release smif v1.3.2

[tomalrussell]

Release checklist:

• [x] create a release branch
• [x] update CHANGELOG with notes on features and fixes since last release.
• [x] update AUTHORS if necessary
• [x] create and push an annotated tag
• [x] open a pull request
• [x] wait (~15 minutes) for tests to pass
• [x] check that deploy stage ran as expected, new version available on https://pypi.org/project/smif/#history
• [x] create a GitHub release for the tag
• [x] wait (~1 day) for conda bot to open PR on https://github.com/conda-forge/smif-feedstock
• [x] check dependencies/versions/lints and merge to release conda package

See more notes in https://smif.readthedocs.io/en/latest/developers.html#releases

[tomalrussell]

Release failed to deploy - seems to be a dirty checkout of tag v1.3.2 ??

https://travis-ci.com/github/nismod/smif/jobs/458409829

[tomalrussell]

Travis install script was using npm install which may modify package-lock.json and so cause git to see it as a dirty checkout - switching to npm ci fixed this.