add note about pivot_table() enhancement in whatsnew. add PR reference to test

Author: cscanlin

doc/source/whatsnew/v0.18.0.txt

@@ -200,6 +200,7 @@ Other enhancements
 - ``Series`` gained an ``is_unique`` attribute (:issue:`11946`)
 - ``DataFrame.quantile`` and ``Series.quantile`` now accept ``interpolation`` keyword (:issue:`10174`).
 - ``DataFrame.select_dtypes`` now allows the ``np.float16`` typecode (:issue:`11990`)
+- ``pivot_table()`` now accepts most iterables for the ``values`` parameter (:issue:`12017`)
 
 .. _whatsnew_0180.api_breaking:
 

pandas/tools/tests/test_pivot.py

@@ -737,6 +737,7 @@ def test_pivot_dtaccessor(self):
         tm.assert_frame_equal(result, expected)
 
     def test_pivot_table_with_iterator_values(self):
+        # GH 12017
         aggs = {'D': 'sum', 'E': 'mean'}
 
         pivot_values_list = pd.pivot_table(