Merge pull request #238 from libp2p/fix-global-listen-in-tests

only listen on localhost in tests

dial_test.go

@@ -153,7 +153,7 @@ func TestSimultDials(t *testing.T) {
 
 func newSilentPeer(t *testing.T) (peer.ID, ma.Multiaddr, net.Listener) {
 	dst := testutil.RandPeerIDFatal(t)
-	lst, err := net.Listen("tcp4", ":0")
+	lst, err := net.Listen("tcp4", "localhost:0")
 	if err != nil {
 		t.Fatal(err)
 	}