Recently put together Versionary. A plug which makes it simple to handle versioning in your API. It hasn't been released yet but is ready to go. Was hoping to get some feedback from the community before publishing it.
Version 0.1.0 of Versionary has been released.
GitHub: https://github.com/sticksnleaves/versionaryDocumentation: https://hexdocs.pm/versionary/api-reference.html