Update explainer_manager.py to change docs from MimicWrapper to Mimic…

…Explainer (microsoft#2240)

responsibleai/responsibleai/managers/explainer_manager.py

@@ -117,7 +117,7 @@ def _initialize_surrogate_model(self):
             self._surrogate_model = LinearExplainableModel
 
     def _compute_explanations(self, local: bool, data: Any):
-        """Compute explanations using MimicWrapper.
+        """Compute explanations using MimicExplainer.
 
         :param local: True if local explanations are requested
                 and False otherwise.