refactor(sointu): change the name of AudioSink into AudioOutput

The interface is never used as anything else as Output so trying to generalize as something more vague like Sink made no sense.

audio.go

@@ -1,8 +1,8 @@
 package sointu
 
-// AudioSink represents something where we can send audio e.g. audio output.
+// AudioOutput represents something where we can send audio e.g. audio output.
 // WriteAudio should block if not ready to accept audio e.g. buffer full.
-type AudioSink interface {
+type AudioOutput interface {
 	WriteAudio(buffer []float32) error
 	Close() error
 }
@@ -11,9 +11,9 @@ type AudioSink interface {
 // one AudioContext at a time. The interface is implemented at least by
 // oto.OtoContext, but in future we could also mock it.
 //
-// AudioContext is used to create one or more AudioSinks with Output(); each can
-// be used to output separate sound & closed when done.
+// AudioContext is used to create one or more AudioOutputs with Output(); each
+// can be used to output separate sound & closed when done.
 type AudioContext interface {
-	Output() AudioSink
+	Output() AudioOutput
 	Close() error
 }

oto/oto.go

@@ -13,7 +13,7 @@ type OtoOutput struct {
 	tmpBuffer []byte
 }
 
-func (c *OtoContext) Output() sointu.AudioSink {
+func (c *OtoContext) Output() sointu.AudioOutput {
 	return &OtoOutput{player: (*oto.Context)(c).NewPlayer(), tmpBuffer: make([]byte, 0)}
 }