Request lib doesn't handle undefined response body properly

[rmiyashiro]

If the body of the response is undefined, Request will call JSON.parse() on it and ignore the resulting exception:

https://github.com/request/request/blob/master/request.js#L1038-L1042

Also, if the json: true option is not used, Request will convert any undefined body into an empty string:

https://github.com/request/request/blob/master/request.js#L1045-L1047

Not sure if that second one is really a problem. It's just a little odd. The first issue could easily be addressed by just doing some simple checks before calling parse() though.