Add linting to the CI build

[ross-p-smith]

Once #243 has merged - we should add linting to the PR CI

This issue is for a: (mark with an x)

- [ ] bug report -> please search issues before submitting
- [x] feature request
- [ ] documentation issue or request
- [ ] regression (a behavior that used to work and stopped in a new release)

[ross-p-smith]

Fixed in #281