Add missing field to offset fetch/commit responses

protocol/offset_commit_response.go

@@ -1,10 +1,16 @@
 package protocol
 
 type OffsetCommitResponse struct {
+	ClientID string
 	Errors map[string]map[int32]KError
 }
 
 func (r *OffsetCommitResponse) decode(pd packetDecoder) (err error) {
+	r.ClientID, err = pd.getString()
+	if err != nil {
+		return err
+	}
+
 	numTopics, err := pd.getArrayCount()
 	if err != nil {
 		return err

protocol/offset_fetch_response.go

@@ -23,10 +23,16 @@ func (r *OffsetFetchResponseBlock) decode(pd packetDecoder) (err error) {
 }
 
 type OffsetFetchResponse struct {
+	ClientID string
 	Blocks map[string]map[int32]*OffsetFetchResponseBlock
 }
 
 func (r *OffsetFetchResponse) decode(pd packetDecoder) (err error) {
+	r.ClientID, err = pd.getString()
+	if err != nil {
+		return err
+	}
+
 	numTopics, err := pd.getArrayCount()
 	if err != nil {
 		return err