add response schemas and types

[robot-ranger]

I added minimal response content spec to swagger generation. This should enable the use of https://github.com/swagger-api/swagger-codegen to generate functional swagger clients; returning the entire response doc from the agent.

I have tested with a generated python swagger client. I assume, but have not tested, it should enable functional, auto-generated, clients in any language swagger-codegen supports.

@mnoomnoo helped; i cant take all the credit.

fixes #515

[robot-ranger]

hold off on this. i guess the order of the content responses implies the "default" response type. json has to be listed first in order for swagger-codegen to recognize the response type as 'object' instead of 'str'. this distinction is critical for json responses; otherwise you get a json-like string back instead of an actual json (single quotes ' instead of json spec double quotes ")

ill submit another PR; dont merge this one.

[wsobel]

Got it. I'll wait.