Add a constructor for anonymous usage (#124)

Fixes #123

README.MD

@@ -16,7 +16,8 @@ import (
 )
 
 func main() {
-	client := twitch.NewClient("justinfan123123", "oauth:123123123")
+	// or client := twitch.NewAnonymousClient() for an anonymous user (no write capabilities)
+	client := twitch.NewClient("yourtwitchusername", "oauth:123123123")
 
 	client.OnPrivateMessage(func(message twitch.PrivateMessage) {
 		fmt.Println(message.Message)

client.go

@@ -415,6 +415,12 @@ func NewClient(username, oauth string) *Client {
 	}
 }
 
+// NewAnonymousClient to create a new client without login requirements (anonymous user)
+// Do note that the Say and Whisper functions will be ineffectual when using this constructor
+func NewAnonymousClient() *Client {
+	return NewClient("justinfan123123", "oauth:59301")
+}
+
 // OnConnect attach callback to when a connection has been established
 func (c *Client) OnConnect(callback func()) {
 	c.onConnect = callback

client_test.go

@@ -85,8 +85,16 @@ func newTestClient(host string) *Client {
 	return client
 }
 
+func newAnonymousTestClient(host string) *Client {
+	client := NewAnonymousClient()
+	client.IrcAddress = host
+
+	return client
+}
+
 func connectAndEnsureGoodDisconnect(t *testing.T, client *Client) chan struct{} {
 	c := make(chan struct{})
+
 	go func() {
 		err := client.Connect()
 		assertErrorsEqual(t, ErrClientDisconnected, err)
@@ -423,6 +431,53 @@ func TestFullConnectAndDisconnect(t *testing.T) {
 	<-server.stopped
 }
 
+func TestCanConnectAndAuthenticateAnonymous(t *testing.T) {
+	t.Parallel()
+	const oauthCode = "oauth:59301"
+	waitPass := make(chan struct{})
+	waitServerConnect := make(chan struct{})
+	waitClientConnect := make(chan struct{})
+
+	var received string
+
+	server := startServer2(t, closeOnConnect(waitServerConnect), closeOnPassReceived(&received, waitPass))
+
+	client := newAnonymousTestClient(server.host)
+	client.OnConnect(clientCloseOnConnect(waitClientConnect))
+	clientDisconnected := connectAndEnsureGoodDisconnect(t, client)
+
+	// Wait for server to acknowledge connection
+	if !waitWithTimeout(waitServerConnect) {
+		t.Fatal("no successful connection")
+	}
+
+	// Wait for client to acknowledge connection
+	if !waitWithTimeout(waitClientConnect) {
+		t.Fatal("no successful connection")
+	}
+
+	// Wait to receive password
+	select {
+	case <-waitPass:
+	case <-time.After(time.Second * 3):
+		t.Fatal("no oauth read")
+	}
+
+	assertStringsEqual(t, "PASS "+oauthCode, received)
+
+	// Disconnect client from server
+	err := client.Disconnect()
+	if err != nil {
+		t.Error("Error during disconnect:" + err.Error())
+	}
+
+	// Wait for client to be fully disconnected
+	<-clientDisconnected
+
+	// Wait for server to be fully disconnected
+	<-server.stopped
+}
+
 func TestCanDisconnect(t *testing.T) {
 	t.Parallel()
 	wait := make(chan struct{})