Merge pull request #43 from soheilhy/dev/go18

Fix tests for Go 1.8+

.travis.yml

@@ -4,6 +4,7 @@ go:
   - 1.5
   - 1.6
   - 1.7
+  - 1.8
   - tip
 
 matrix:

cmux_test.go

@@ -42,7 +42,7 @@ const (
 )
 
 func safeServe(errCh chan<- error, muxl CMux) {
-	if err := muxl.Serve(); !strings.Contains(err.Error(), "use of closed network connection") {
+	if err := muxl.Serve(); !strings.Contains(err.Error(), "use of closed") {
 		errCh <- err
 	}
 }