Update reference

Update the 'measurements' reference in samples.py to refer to
the section that describes the supported sample types.

Change-Id: I75913cdac6780d2cb6498999830ebb3734a8457e

ceilometer/api/controllers/v2/samples.py

@@ -45,7 +45,7 @@ class Sample(base.Base):
     "The meter name this sample is for."
 
     type = wtypes.Enum(str, *sample.TYPES)
-    "The meter type (see :ref:`measurements`)"
+    "The meter type (see :ref:`meter_types`)"
 
     unit = wtypes.text
     "The unit of measure."

doc/source/new_meters.rst

@@ -24,6 +24,7 @@ from other external components. If you would like to add new meters to the
 currently existing ones, you need to follow the guidelines given in this
 section.
 
+.. _meter_types:
 
 Types
 =====