Allow non-default root URLs

client.go

@@ -16,6 +16,7 @@ type Client interface {
 	AccountSid() string
 	AuthToken() string
 	RootUrl() string
+	UpdateRoot(string)
 	get(url.Values, string) ([]byte, error)
 	post(url.Values, string) ([]byte, error)
 	delete(string) error
@@ -172,3 +173,7 @@ func (client *TwilioClient) buildUri(parts ...string) string {
 	}
 	return strings.Join(newParts, "/")
 }
+
+func (client *TwilioClient) UpdateRoot(root string) {
+	client.rootUrl = root + "/" + VERSION + "/Accounts/" + client.accountSid
+}

mock_client.go

@@ -36,3 +36,6 @@ func (client *MockClient) delete(uri string) error {
 	args := client.Mock.Called(nil, uri)
 	return args.Error(1)
 }
+
+func (client *MockClient) UpdateRoot(_ string) {
+}