move SmartDeviceException to SmartDevice, and remove types.py complet… (#95)

* move SmartDeviceException to SmartDevice, and remove types.py completely. fixes #94

* do not import skipIf anymore

pyHS100/smartdevice.py

@@ -20,12 +20,18 @@ import warnings
 from collections import defaultdict
 from typing import Any, Dict, List, Tuple, Optional
 
-from .types import SmartDeviceException
 from .protocol import TPLinkSmartHomeProtocol
 
 _LOGGER = logging.getLogger(__name__)
 
 
+class SmartDeviceException(Exception):
+    """
+    SmartDeviceException gets raised for errors reported by device.
+    """
+    pass
+
+
 class SmartDevice(object):
     # possible device features
     FEATURE_ENERGY_METER = 'ENE'