is_collection: add test that range function is not iterable

Replicates graphql/graphql-js@ab329e9

Author: Cito

tests/pyutils/test_is_collection.py

@@ -46,6 +46,9 @@ def a_values_view_is_a_collection():
     def a_range_is_a_collection():
         assert is_collection(range(10)) is True
 
+    def range_function_itself_is_not_a_collection():
+        assert is_collection(range) is False
+
     def an_infinite_generator_is_not_a_collection():
         assert is_collection(count()) is False