bump version (#123)

Author: cartertinney

azure-iot-device/setup.py

@@ -30,7 +30,7 @@
 
 setup(
     name="azure-iot-device",
-    version="2.0.0-preview.6",
+    version="2.0.0-preview.7",
     description="Microsoft Azure IoT Device Library",
     license="MIT License",
     url="https://github.com/Azure/azure-iot-sdk-python-preview",