Swagger docs for the full API

[dberesford]

This PR landed Swagger support for Hapi: CoderDojo/cp-zen-platform#709. Internally uses the Hapi-Swagger module.

To see it in action, open http://localhost:8000/documentation

The PR also has just one example of how to add Swagger config to a route API:

https://github.com/CoderDojo/cp-zen-platform/blob/93d06f8530ff9c5afbb62ed3a2edf59ac04b4255/lib/sys.js#L11-L15

The remainder of the API needs to be documented in a similar fashion, a non-trivial amount of work! All the routes in nearly all the files in https://github.com/CoderDojo/cp-zen-platform/tree/master/lib.

Furthermore, Joi validation should to be added to most endpoints, if this is in place it both validates the API parameters as well as feeding in to the Swagger docs (a double win!). See http://hapijs.com/tutorials/validation.

For more on Swagger, see Swagger.io.

[dberesford]

Big thanks to @mihaidma for swaggerising and adding joi validation to the dojos api: CoderDojo/cp-zen-platform#725. This is a really good example for how to do this for the rest of the API (badges, events, users, etc)

[meetjonblack]

I added some swag and joi to the agreements API. I just did a PR. If this is good, then I can try to knock out the others.