REST API: 6.0 Change log

Story
As a consumer of the REST APIs I want a way to see the changes to the OpenAPI spec in each build compared to the previous release so that I can plan accordingly and keep up with changes.

Acceptance Criteria

• Diff reports have been manually prepared highlighting the differences between the latest 6.0 branch and the latest 5.2.N branch for each yaml file.
• The diff reports have been checked into the RAE codebase under a folder called changelogs e.g.
  • /changelogs/core-5.1-5.2.html
  • /changelogs/core-5.2-6.0.html

Notes

• The report does not need to be "pretty", the goal is to produce the list for use in other places, release notes, for example.
• There are a couple of libraries that could be useful:
  • https://github.com/Sayi/swagger-diff
  • https://github.com/civisanalytics/swagger-diff

The first one is Java based and has been tested manually, it produces a report but unfortunately it's rendered with some Japanese characters. The second library is Ruby based, there may well be others too. Alternatively, the swagger parser could be used to write our own "diff" to get exactly what we need.