Use a JSON schema validator

A JSON schema validator should be used in the routers to make sure the data they passed up was correct. From looking at options, it seems [is-my-json-valid](https://github.com/mafintosh/is-my-json-valid) would work. I decided on this one from looking at [this comparison](http://cosmicrealms.com/blog/2014/08/29/benchmark-of-node-dot-js-json-validation-modules-part-3/)
