Release 1821
Trello card
Context
We are removing the legacy, direct CRM integration code from the app now that we are happy that the API integration is working as expected. This will involve a number of PRs to incrementally remove the old code.
Changes proposed in this pull request
Remove legacy code from the two remaining core classes (ContactFetcher and GitisAuthenticate concern). Many specs end up calling code in these classes so it meant I had to go and update a bunch of failing tests to use the correct candidate model type and mocking of the API.
Guidance to review
I would have liked to have done this in smaller changes but the way its all tied together means it needs to be done in a bit of a big bang to get everything green.