Golang，Cors和angularjs-标头缺失

I'm using rs/cors in my Go API to allow my Angularjs app to make direct requests. I've added the following code to configure CORS:

crs := cors.New(cors.Options{AllowCredentials: true})
n.Use(crs) //Negroni include

but I'm getting the No 'Access-Control-Allow-Origin' header is present on the requested resource message in the browser when I make a request.

My request looks like this:

var req = {
    method: 'POST',
    url: endPoint + version + method,
    headers: {
        'Authorization': 'Basic ' + btoa(':' + appId)
    },
    data: params
}

$http(req).
    success(function(data, status, headers, config) {
        callback(null, data);
    }).
    error(function(data, status, headers, config) {
        callback(data);
    });

How can I get round this?

Fixed it! I noticed that a few different headers were being sent with the request and I had to explicitly allow all of them.

AllowedHeaders: []string{"accept", "authorization", "content-type"}

I hope this helps someone.