this is a checking of the [amalgamated][1] source of the json-cpp parser. It's
a great parser and this way we can just include it in the test build without
having to build another vendor library and dealing with their build system.
This gives us the ability to parse output from httpbin for better unit tests.

[1]: https://github.com/open-source-parsers/jsoncpp#generating-amalgamated-source-and-header

this adds a test case to each suite that uses json-cpp to parse the response
body and make sure we get the correct response back. Now there is an easy to
use example for future tests in each suite.

this fixes #23