Run (make vendor) for the first time.

This primarily adds vendor/github.com/containers/image/docs/ ,
but also updates other dependencies that are not pinned to a specific
commit.

vendor/golang.org/x/net/http2/frame.go

@@ -14,8 +14,8 @@ import (
 	"strings"
 	"sync"
 
+	"golang.org/x/net/http/httpguts"
 	"golang.org/x/net/http2/hpack"
-	"golang.org/x/net/lex/httplex"
 )
 
 const frameHeaderLen = 9
@@ -1462,7 +1462,7 @@ func (fr *Framer) readMetaFrame(hf *HeadersFrame) (*MetaHeadersFrame, error) {
 		if VerboseLogs && fr.logReads {
 			fr.debugReadLoggerf("http2: decoded hpack field %+v", hf)
 		}
-		if !httplex.ValidHeaderFieldValue(hf.Value) {
+		if !httpguts.ValidHeaderFieldValue(hf.Value) {
 			invalid = headerFieldValueError(hf.Value)
 		}
 		isPseudo := strings.HasPrefix(hf.Name, ":")