Add ControllerApplication.shutdown() method. (#26)

Goes along with zigpy/zigpy#133

Author: Adminiuga

tests/test_application.py

@@ -224,3 +224,10 @@ def test_handle_reply_unexpected(app):
     assert app.handle_message.call_args[0][6] == tsn
     assert app.handle_message.call_args[0][7] == mock.sentinel.command_id
     assert app.handle_message.call_args[0][8] == mock.sentinel.args
+
+
+@pytest.mark.asyncio
+async def test_shutdown(app):
+    app._api.close = mock.MagicMock()
+    await app.shutdown()
+    assert app._api.close.call_count == 1

zigpy_deconz/zigbee/application.py

@@ -35,6 +35,10 @@ async def _reset_watchdog(self):
             await self._api.write_parameter(NETWORK_PARAMETER['watchdog_ttl'][0], 3600)
             await asyncio.sleep(1200)
 
+    async def shutdown(self):
+        """Shutdown application."""
+        self._api.close()
+
     async def startup(self, auto_form=False):
         """Perform a complete application startup"""
         r = await self._api.version()