Added the start of RPC + removed proxy functions.

* Set the listener of the server when opened.

* refactor server RPC.

* deleted proxy functions + moved TCPPeer to tcp file

* implemented the start of JSON-RPC

* changed string port args to int

* added peerCount.

* Start a server with startOpts

* Updated README

pkg/network/server_test.go

@@ -24,6 +24,20 @@ func TestHandleVersion(t *testing.T) {
 	}
 }
 
+func TestPeerCount(t *testing.T) {
+	s := NewServer(ModeDevNet)
+	go s.loop()
+
+	lenPeers := 10
+	for i := 0; i < lenPeers; i++ {
+		s.register <- NewLocalPeer(s)
+	}
+
+	if have, want := s.peerCount(), lenPeers; want != have {
+		t.Fatalf("expected %d connected peers got %d", want, have)
+	}
+}
+
 func TestHandleAddrCmd(t *testing.T) {
 	// todo
 }