Added ability to change the description and parameters of the API endpoints generated by grape-swagger.

[dblock]

You can now specify additional options for the API endpoints generated by grape-swagger, including the description. In our API we also inject additional options that are processed by middleware (for authentication).

add_swagger_documentation \
   api_documentation: { desc: 'First', params: { x: 1 }, xx: 11 },
   specific_api_documentation: { desc: 'Second', params: { y: 42 }, yy: 4242 }

I am not in love with the names of these options (open to suggestions).

@CraigCottingham, mind taking a look?

[krisalyssa]

@dblock The names "api_documentation" and "specific_api_documentation" look okay to me, but to be honest I'm not entirely clear on what in Swagger these are overriding. Is it :description in sections 5.1.3 and 5.2.2 of https://github.com/wordnik/swagger-spec/blob/master/versions/1.2.md respectively?

[dblock]

It's the summary of the operation, but we always called it description in the Grape context. I'll merge this, and maybe lets clarify the docs a bit about what is overriding what? Feel free to make PRs and I'll take a look at that too.