Don't let lower/upper case throw me off.

src/saml2/attribute_converter.py

@@ -425,11 +425,19 @@ class AttributeConverter(object):
         :return: An Attribute instance
         """
         try:
+            _attr = self._to[attr]
+        except KeyError:
+            try:
+                _attr = self._to[attr.to_lower()]
+            except:
+                _attr = ''
+
+        if _attr:
             return factory(saml.Attribute,
-                           name=self._to[attr],
+                           name=_attr,
                            name_format=self.name_format,
                            friendly_name=attr)
-        except KeyError:
+        else:
             return factory(saml.Attribute, name=attr)
 
     def from_format(self, attr):

src/saml2/entity_category/incommon.py

@@ -8,4 +8,3 @@ RELEASE = {
                                "eduPersonScopedAffiliation", "mail",
                                "givenName", "sn", "displayName"]
 }
-