Update IP for test

test_gandi_ddns.py

 import gandi_ddns as script
+import socket
 
 def test_get_ip():
-    assert script.get_ip() == 'test-toto'
\ No newline at end of file
+    assert script.get_ip() == socket.gethostbyname(socket.gethostname())
\ No newline at end of file