Fix exceptions handling in create_from_yaml (#298)

Author: tomplus

examples/example2.py

@@ -22,7 +22,7 @@ async def main():
     print("Ended.")
     # An explicit close is necessary to stop the stream
     # or use async context manager like in example4.py
-    w.close()
+    await w.close()
 
 
 if __name__ == '__main__':

kubernetes_asyncio/utils/create_from_yaml.py

@@ -70,7 +70,7 @@ async def create_from_yaml(
                                                  **kwargs)
                 k8s_objects.append(created)
             except FailToCreateError as failure:
-                api_exceptions.extend(failure)
+                api_exceptions.append(failure)
 
     # In case we have exceptions waiting for us, raise them
     if api_exceptions: