Explicitly set 'builders' option

stephenfin · stephenfin · commit e611aa6314b2 · 2017-04-19T10:30:21.000+01:00
An upcoming release of pbr will require explicitly stating which
builders are requested, rather than defaulting to html and man. Head off
any potential impact this may cause by explicitly setting this
configuration now.

Change-Id: I243ca33f5459009f9a9670ec5e0ad67b04760f35
diff --git a/setup.cfg b/setup.cfg
@@ -702,6 +702,7 @@ autodoc_tree_excludes =
     openstackclient/tests/*
 
 [build_sphinx]
+builders = html,man
 all-files = 1
 warning-is-error = 1
 source-dir = doc/source
