refs linear.app/tryghost/issue/CORE-74/improve-the-test-situation
- this commit adds the codecov GitHub Action into CI so we can upload
coverage reports
- the coverage files need to be in XML for them to work with
codecov, so this commit also adds cobertura (XML) as a reporter
refs https://github.com/TryGhost/Team/issues/1091
The Offers feature needs to be able to add and remove redirects to Ghost
- which is very similar to the custom redirects functionality. Here we've
pulled out the core of the dynamic redirect part of custom redirects so
that it can be used by both features and have code shared between them.
