Fix Warnings section in validate (#335)

* Add Warnings to validate tests

* Add Warnings to allowed sections.

Author: MatthewFlamm

numpydoc/tests/test_validate.py

@@ -384,6 +384,27 @@ def say_hello():
         else:
             return None
 
+    def warnings(self):
+        """
+        Do one thing.
+
+        Sometimes, this function does other things.
+
+        Warnings
+        --------
+        This function may produce side effects when some condition
+        is met.
+
+        See Also
+        --------
+        related : Something related.
+
+        Examples
+        --------
+        >>> result = 1 + 1
+        """
+        pass
+
     def multiple_variables_on_one_line(self, matrix, a, b, i, j):
         """
         Swap two values in a matrix.
@@ -1039,6 +1060,7 @@ def test_good_class(self, capsys):
             "no_returns",
             "empty_returns",
             "multiple_variables_on_one_line",
+            "warnings",
         ],
     )
     def test_good_functions(self, capsys, func):

numpydoc/validate.py

@@ -27,6 +27,7 @@
     "Other Parameters",
     "Raises",
     "Warns",
+    "Warnings",
     "See Also",
     "Notes",
     "References",