Support binary responses with andReturn

[mjones-vsat]

Right now binary responses don't seem to work as intended due to extensive use of String. What would it take to allow binary responses to be mocked?

[rohanKanojia]

Umm, Could you please elaborate your use case a bit?

[mjones-vsat]

We are using protobuf instead of JSON, and the following doesn't work:

message = getProtoMessage();
server.expect().withPath("/api/foo").andReturn(200, message.toByteArray()).once();

[rohanKanojia]

@vsmteam : Could you please raise a PR to support this?