IPAError now more appropriately subclasses from StandardError instead of Exception

ipalib/errors.py

@@ -89,7 +89,7 @@ def check_isinstance(value, type_, name, allow_none=False):
     return value
 
 
-class IPAError(Exception):
+class IPAError(StandardError):
     """
     Base class for all custom IPA errors.
 

tests/test_ipalib/test_errors.py

@@ -141,7 +141,7 @@ class test_IPAError(ClassChecker):
         """
         Test the `ipalib.errors.IPAError` exception.
         """
-        assert self.cls.__bases__ == (Exception,)
+        assert self.cls.__bases__ == (StandardError,)
 
     def test_init(self):
         """