diff --git a/vendor/github.com/Shopify/sarama/offset_commit_request.go b/vendor/github.com/Shopify/sarama/offset_commit_request.go
new file mode 100644
index 0000000..1ec583e
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/offset_commit_request.go
@@ -0,0 +1,210 @@
+package sarama
+
+import "errors"
+
+// ReceiveTime is a special value for the timestamp field of Offset Commit Requests which
+// tells the broker to set the timestamp to the time at which the request was received.
+// The timestamp is only used if message version 1 is used, which requires kafka 0.8.2.
+const ReceiveTime int64 = -1
+
+// GroupGenerationUndefined is a special value for the group generation field of
+// Offset Commit Requests that should be used when a consumer group does not rely
+// on Kafka for partition management.
+const GroupGenerationUndefined = -1
+
+type offsetCommitRequestBlock struct {
+	offset    int64
+	timestamp int64
+	metadata  string
+}
+
+func (b *offsetCommitRequestBlock) encode(pe packetEncoder, version int16) error {
+	pe.putInt64(b.offset)
+	if version == 1 {
+		pe.putInt64(b.timestamp)
+	} else if b.timestamp != 0 {
+		Logger.Println("Non-zero timestamp specified for OffsetCommitRequest not v1, it will be ignored")
+	}
+
+	return pe.putString(b.metadata)
+}
+
+func (b *offsetCommitRequestBlock) decode(pd packetDecoder, version int16) (err error) {
+	if b.offset, err = pd.getInt64(); err != nil {
+		return err
+	}
+	if version == 1 {
+		if b.timestamp, err = pd.getInt64(); err != nil {
+			return err
+		}
+	}
+	b.metadata, err = pd.getString()
+	return err
+}
+
+type OffsetCommitRequest struct {
+	ConsumerGroup           string
+	ConsumerGroupGeneration int32  // v1 or later
+	ConsumerID              string // v1 or later
+	RetentionTime           int64  // v2 or later
+
+	// Version can be:
+	// - 0 (kafka 0.8.1 and later)
+	// - 1 (kafka 0.8.2 and later)
+	// - 2 (kafka 0.9.0 and later)
+	// - 3 (kafka 0.11.0 and later)
+	// - 4 (kafka 2.0.0 and later)
+	Version int16
+	blocks  map[string]map[int32]*offsetCommitRequestBlock
+}
+
+func (r *OffsetCommitRequest) encode(pe packetEncoder) error {
+	if r.Version < 0 || r.Version > 4 {
+		return PacketEncodingError{"invalid or unsupported OffsetCommitRequest version field"}
+	}
+
+	if err := pe.putString(r.ConsumerGroup); err != nil {
+		return err
+	}
+
+	if r.Version >= 1 {
+		pe.putInt32(r.ConsumerGroupGeneration)
+		if err := pe.putString(r.ConsumerID); err != nil {
+			return err
+		}
+	} else {
+		if r.ConsumerGroupGeneration != 0 {
+			Logger.Println("Non-zero ConsumerGroupGeneration specified for OffsetCommitRequest v0, it will be ignored")
+		}
+		if r.ConsumerID != "" {
+			Logger.Println("Non-empty ConsumerID specified for OffsetCommitRequest v0, it will be ignored")
+		}
+	}
+
+	if r.Version >= 2 {
+		pe.putInt64(r.RetentionTime)
+	} else if r.RetentionTime != 0 {
+		Logger.Println("Non-zero RetentionTime specified for OffsetCommitRequest version <2, it will be ignored")
+	}
+
+	if err := pe.putArrayLength(len(r.blocks)); err != nil {
+		return err
+	}
+	for topic, partitions := range r.blocks {
+		if err := pe.putString(topic); err != nil {
+			return err
+		}
+		if err := pe.putArrayLength(len(partitions)); err != nil {
+			return err
+		}
+		for partition, block := range partitions {
+			pe.putInt32(partition)
+			if err := block.encode(pe, r.Version); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
+func (r *OffsetCommitRequest) decode(pd packetDecoder, version int16) (err error) {
+	r.Version = version
+
+	if r.ConsumerGroup, err = pd.getString(); err != nil {
+		return err
+	}
+
+	if r.Version >= 1 {
+		if r.ConsumerGroupGeneration, err = pd.getInt32(); err != nil {
+			return err
+		}
+		if r.ConsumerID, err = pd.getString(); err != nil {
+			return err
+		}
+	}
+
+	if r.Version >= 2 {
+		if r.RetentionTime, err = pd.getInt64(); err != nil {
+			return err
+		}
+	}
+
+	topicCount, err := pd.getArrayLength()
+	if err != nil {
+		return err
+	}
+	if topicCount == 0 {
+		return nil
+	}
+	r.blocks = make(map[string]map[int32]*offsetCommitRequestBlock)
+	for i := 0; i < topicCount; i++ {
+		topic, err := pd.getString()
+		if err != nil {
+			return err
+		}
+		partitionCount, err := pd.getArrayLength()
+		if err != nil {
+			return err
+		}
+		r.blocks[topic] = make(map[int32]*offsetCommitRequestBlock)
+		for j := 0; j < partitionCount; j++ {
+			partition, err := pd.getInt32()
+			if err != nil {
+				return err
+			}
+			block := &offsetCommitRequestBlock{}
+			if err := block.decode(pd, r.Version); err != nil {
+				return err
+			}
+			r.blocks[topic][partition] = block
+		}
+	}
+	return nil
+}
+
+func (r *OffsetCommitRequest) key() int16 {
+	return 8
+}
+
+func (r *OffsetCommitRequest) version() int16 {
+	return r.Version
+}
+
+func (r *OffsetCommitRequest) requiredVersion() KafkaVersion {
+	switch r.Version {
+	case 1:
+		return V0_8_2_0
+	case 2:
+		return V0_9_0_0
+	case 3:
+		return V0_11_0_0
+	case 4:
+		return V2_0_0_0
+	default:
+		return MinVersion
+	}
+}
+
+func (r *OffsetCommitRequest) AddBlock(topic string, partitionID int32, offset int64, timestamp int64, metadata string) {
+	if r.blocks == nil {
+		r.blocks = make(map[string]map[int32]*offsetCommitRequestBlock)
+	}
+
+	if r.blocks[topic] == nil {
+		r.blocks[topic] = make(map[int32]*offsetCommitRequestBlock)
+	}
+
+	r.blocks[topic][partitionID] = &offsetCommitRequestBlock{offset, timestamp, metadata}
+}
+
+func (r *OffsetCommitRequest) Offset(topic string, partitionID int32) (int64, string, error) {
+	partitions := r.blocks[topic]
+	if partitions == nil {
+		return 0, "", errors.New("No such offset")
+	}
+	block := partitions[partitionID]
+	if block == nil {
+		return 0, "", errors.New("No such offset")
+	}
+	return block.offset, block.metadata, nil
+}