fix: Return future.result from run_until_complete (#73)

Author: kyleconroy

bundled/poll_loop.py

@@ -150,7 +150,7 @@ def run_until_complete(self, future):
             if self.exception is not None:
                 raise self.exception
 
-        future.result()
+        return future.result()
 
     def is_running(self):
         return self.running