Implement git refs API for listing references (branches, tags and other) (#5354)

* Inital routes to git refs api

* Git refs API implementation

* Update swagger

* Fix copyright

* Make swagger happy add basic test

* Fix test

* Fix test again :)

vendor/gopkg.in/src-d/go-git.v4/utils/binary/write.go

@@ -0,0 +1,50 @@
+package binary
+
+import (
+	"encoding/binary"
+	"io"
+)
+
+// Write writes the binary representation of data into w, using BigEndian order
+// https://golang.org/pkg/encoding/binary/#Write
+func Write(w io.Writer, data ...interface{}) error {
+	for _, v := range data {
+		if err := binary.Write(w, binary.BigEndian, v); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func WriteVariableWidthInt(w io.Writer, n int64) error {
+	buf := []byte{byte(n & 0x7f)}
+	n >>= 7
+	for n != 0 {
+		n--
+		buf = append([]byte{0x80 | (byte(n & 0x7f))}, buf...)
+		n >>= 7
+	}
+
+	_, err := w.Write(buf)
+
+	return err
+}
+
+// WriteUint64 writes the binary representation of a uint64 into w, in BigEndian
+// order
+func WriteUint64(w io.Writer, value uint64) error {
+	return binary.Write(w, binary.BigEndian, value)
+}
+
+// WriteUint32 writes the binary representation of a uint32 into w, in BigEndian
+// order
+func WriteUint32(w io.Writer, value uint32) error {
+	return binary.Write(w, binary.BigEndian, value)
+}
+
+// WriteUint16 writes the binary representation of a uint16 into w, in BigEndian
+// order
+func WriteUint16(w io.Writer, value uint16) error {
+	return binary.Write(w, binary.BigEndian, value)
+}