Add lint for filenames

We have established a pattern of Alpha and underscores for filenames.
This adds a hook to keep this pattern going. Also fixes a misnamed file
I found in the process.

Resolves #456

rtptransceiver.go

@@ -0,0 +1,46 @@
+package webrtc
+
+import (
+	"github.com/pkg/errors"
+)
+
+// RTPTransceiver represents a combination of an RTPSender and an RTPReceiver that share a common mid.
+type RTPTransceiver struct {
+	Mid       string
+	Sender    *RTPSender
+	Receiver  *RTPReceiver
+	Direction RTPTransceiverDirection
+	// currentDirection RTPTransceiverDirection
+	// firedDirection   RTPTransceiverDirection
+	// receptive bool
+	stopped bool
+}
+
+func (t *RTPTransceiver) setSendingTrack(track *Track) error {
+	t.Sender.track = track
+
+	switch t.Direction {
+	case RTPTransceiverDirectionRecvonly:
+		t.Direction = RTPTransceiverDirectionSendrecv
+	case RTPTransceiverDirectionInactive:
+		t.Direction = RTPTransceiverDirectionSendonly
+	default:
+		return errors.Errorf("Invalid state change in RTPTransceiver.setSending")
+	}
+	return nil
+}
+
+// Stop irreversibly stops the RTPTransceiver
+func (t *RTPTransceiver) Stop() error {
+	if t.Sender != nil {
+		if err := t.Sender.Stop(); err != nil {
+			return err
+		}
+	}
+	if t.Receiver != nil {
+		if err := t.Receiver.Stop(); err != nil {
+			return err
+		}
+	}
+	return nil
+}