新增diff和snap协议

params/caps.go

@@ -3,6 +3,8 @@ package params
 import "blockchain-go/p2p"
 
 var Caps = []p2p.Cap{
+	{Name: "diff", Version: 1},
+	{Name: "snap", Version: 1},
 	{Name: "eth", Version: 65},
 	{Name: "eth", Version: 66},
 	{Name: "eth", Version: 67},