[Finishes #75911106] Create Instantink API gem

- initial functioning commit for gem
- create common library for functions for Agena request specs
- monkey patch rspec API documentation gem method  'resource' to include InstantinkApiDocumentator as mixin
Merge pull request #1 from gemini-google-group/wip_get_gem_to_work

[Finishes #75911106] Create Instantink API gem