Travis config: Add Go 1.10.x, revert 1.4.x to 1.4

1.4.x is missing go vet

.travis.yml

@@ -3,12 +3,13 @@ sudo: false
 
 matrix:
   include:
-    - go: 1.4.x
+    - go: 1.4
     - go: 1.5.x
     - go: 1.6.x
     - go: 1.7.x
     - go: 1.8.x
     - go: 1.9.x
+    - go: 1.10.x
     - go: tip
   allow_failures:
     - go: tip

examples/echo/server.go

@@ -20,6 +20,7 @@ var addr = flag.String("addr", "localhost:8080", "http service address")
 var upgrader = websocket.Upgrader{} // use default options
 
 func echo(w http.ResponseWriter, r *http.Request) {
+	log.Println(r.Header)
 	c, err := upgrader.Upgrade(w, r, nil)
 	if err != nil {
 		log.Print("upgrade:", err)