Enable release notes translation

Releasenote translation publishing is being prepared. 'locale_dirs'
needs to be defined in conf.py to generate translated version of the
release notes.

Note that this repository might not get translated release notes - or
no translations at all - but we add the entry here nevertheless to
prepare for it.

Change-Id: I8f9c1aecc2e2a73709fa128fc246be47495e401d

releasenotes/source/conf.py

@@ -73,3 +73,6 @@ latex_documents = [
 
 # Example configuration for intersphinx: refer to the Python standard library.
 # intersphinx_mapping = {'http://docs.python.org/': None}
+
+# -- Options for Internationalization output ------------------------------
+locale_dirs = ['locale/']