Update/delete vendor files

Refreshed / updated vendor dependencies

Tested with "make".

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alexellis2@gmail.com>

gateway/vendor/github.com/gogo/protobuf/proto/lib_gogo.go

@@ -33,6 +33,14 @@ import (
 	"strconv"
 )
 
+type Sizer interface {
+	Size() int
+}
+
+type ProtoSizer interface {
+	ProtoSize() int
+}
+
 func MarshalJSONEnum(m map[int32]string, value int32) ([]byte, error) {
 	s, ok := m[value]
 	if !ok {