Bug fix: callbacks being called twice when JSON.parse() throws an exception

[netoabel]

In:

try {
    callback(null, JSON.parse(data));
} catch (e) {
    callback(e, data, response);
}

Both callbacks are called, because when JSON.parse() throws the exception, in try, the callback method was already called.

So I changed it to:

try {
    var parsedBody = JSON.parse(body);
} catch (e) {
    callback(e, body, response);
}
callback(null, parsedBody, response);