Improve testing harness to allow tests on real devices (#197)

* test_cli: provide return values to patched objects to avoid warning about non-awaited calls

* test_cli: restore alias after testing

* smartstrip: remove internal update() calls for turn_{on,off}, set_led

* Make sure power is always a float

* Fix discovery tests

* Make tests runnable on real devices

* Add a note about running tests on a real device

* test_strip: run update against the parent device

kasa/tests/test_smartdevice.py

@@ -13,6 +13,7 @@ async def test_state_info(dev):
     assert isinstance(dev.state_information, dict)
 
 
+@pytest.mark.requires_dummy
 async def test_invalid_connection(dev):
     with patch.object(FakeTransportProtocol, "query", side_effect=SmartDeviceException):
         with pytest.raises(SmartDeviceException):
@@ -49,18 +50,22 @@ async def test_state(dev, turn_on):
     orig_state = dev.is_on
     if orig_state:
         await dev.turn_off()
+        await dev.update()
         assert not dev.is_on
         assert dev.is_off
 
         await dev.turn_on()
+        await dev.update()
         assert dev.is_on
         assert not dev.is_off
     else:
         await dev.turn_on()
+        await dev.update()
         assert dev.is_on
         assert not dev.is_off
 
         await dev.turn_off()
+        await dev.update()
         assert not dev.is_on
         assert dev.is_off
 
@@ -71,9 +76,11 @@ async def test_alias(dev):
 
     assert isinstance(original, str)
     await dev.set_alias(test_alias)
+    await dev.update()
     assert dev.alias == test_alias
 
     await dev.set_alias(original)
+    await dev.update()
     assert dev.alias == original