Clean up coverage counting a little bit

common/lib/xmodule/.coveragerc

@@ -5,6 +5,9 @@ source = common/lib/xmodule
 
 [report]
 ignore_errors = True
+exclude_lines =
+    pragma: no cover
+    raise NotImplementedError
 
 [html]
 title = XModule Python Test Coverage Report

common/lib/xmodule/xmodule/modulestore/draft_and_published.py

@@ -69,9 +69,6 @@ class ModuleStoreDraftAndPublished(BranchSettingMixin):
     """
     __metaclass__ = ABCMeta
 
-    def __init__(self, *args, **kwargs):
-        super(ModuleStoreDraftAndPublished, self).__init__(*args, **kwargs)
-
     @abstractmethod
     def delete_item(self, location, user_id, revision=None, **kwargs):
         raise NotImplementedError