Allow _repr_mimebundle_ to accept positional arguments (#38)

Author: davidbrochart

src/ypywidgets/comm.py

@@ -87,7 +87,7 @@ def __init__(
         self._comm = create_widget_comm(comm_data, comm_metadata, comm_id)
         CommProvider(self.ydoc, self._comm)
 
-    def _repr_mimebundle_(self, **kwargs):  # pragma: nocover
+    def _repr_mimebundle_(self, *args, **kwargs):  # pragma: nocover
         plaintext = repr(self)
         if len(plaintext) > 110:
             plaintext = plaintext[:110] + '…'