部署到Appengine时，http.Request具有未定义的字段

I'm working on a web app and I depend on the following code for authentication (I'm using github.com/dgrijalva/jwt-go package):

func ValidateProtectedPage(protectedPage http.HandlerFunc) http.HandlerFunc {
return http.HandlerFunc(func(res http.ResponseWriter, req *http.Request) {
    // If no Auth cookie is set then return a 404 not found
    cookie, err := req.Cookie("Auth")
    if err != nil {
        Forbidden(res)
        return
    }

    // Return a Token using the cookie
    token, err := jwt.ParseWithClaims(cookie.Value, &Claims{}, func(token *jwt.Token) (interface{}, error) {
        // Make sure token's signature wasn't changed
        if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
            return nil, fmt.Errorf("Unexpected siging method")
        }
        return []byte(util.Secret), nil
    })

    if err != nil {
        Forbidden(res)
        return
    }

    // Grab the tokens claims and pass it into the original request
    if claims, ok := token.Claims.(*Claims); ok && token.Valid {
        ctx := context.WithValue(req.Context(), "Auth", *claims)
        protectedPage(res, req.WithContext(ctx))
    } else {
        Forbidden(res)
    }
})}

The issue is, that I'm trying to deploy my app to appengine, and I get the following errors:

planilla-go/controllers/auth.go:45: req.Context undefined (type *http.Request has no field or method Context)
planilla-go/controllers/auth.go:46: req.WithContext undefined (type *http.Request has no field or method WithContext)

From what I read this is due to incompatibilities between appengine's requests and those from go's library, but I couldn't find a workaround yet

Is there a way to wrap or convert the http.Request to use appengine's instead?

Appengine only supports Go 1.6. A bit baffling since it renders my app useless without a major compat overhaul, but that's the current state of the platform