- `example/proxy` is new folder for `example_proxy`.
- `riven` is new folder for the main riven lib.
- Updated metadata to be an array and include HTTP method.
New RiotApi.get_raw_response(...) method similar to existing
RiotApi.get(...) and RiotApi.get_optional(...), but does not parse the
result. Useful for proxies which just want to forward the content body.
Also adds tests to JP of failure cases.