fixed errors with output list and upgraded version

Author: NiveditJain

python-sdk/exospherehost/_version.py

@@ -1 +1 @@
-version = "0.0.7b7"
+version = "0.0.7b8"

python-sdk/exospherehost/runtime.py

@@ -324,7 +324,7 @@ async def _worker(self):
                 if outputs is None:
                     outputs = []
 
-                if isinstance(outputs, BaseNode.Outputs):
+                if not isinstance(outputs, list):
                     outputs = [outputs]
 
                 await self._notify_executed(state["state_id"], outputs)