added auto port find

pytorch_lightning/utils/server.py

@@ -0,0 +1,10 @@
+import socket
+
+s = socket.socket()
+host = socket.gethostname()  # Get local machine name
+port = 12910  # Reserve a port for your service.
+s.bind((host, port))  # Bind to the port
+
+s.listen(5)  # Now wait for client connection.
+while True:
+    c, addr = s.accept()  # Establish connection with client.