Fix wrong function description

Correct function name in description for test function.
Also correct function sample in hot function class `MapMerge`.

Change-Id: I61acec48e4a8365940d3e6e3d0a93d0c58fbda43

heat/engine/hot/functions.py

@@ -704,7 +704,7 @@ class MapMerge(function.Function):
 
     And resolves to::
 
-        {"<k1>": "<v2>", "<k2>": "<v3>"}
+        {"<k1>": "<v3>", "<k2>": "<v2>"}
 
     """
 

heat/tests/clients/test_nova_client.py

@@ -96,7 +96,7 @@ class NovaClientPluginTest(NovaClientPluginTestCase):
         self.assertEqual(expected, observed)
 
     def test_find_flavor_by_name_or_id(self):
-        """Tests the get_flavor_id function."""
+        """Tests the find_flavor_by_name_or_id function."""
         flav_id = str(uuid.uuid4())
         flav_name = 'X-Large'
         my_flavor = mock.MagicMock()