Use Sphinx 1.5 warning-is-error

With pbr 2.0 and Sphinx 1.5, the setting for treat sphinx warnings as
errors is setting warning-is-error in build_sphinx section. Enable this.

Change-Id: I39ffb22c37a05f00cade2fbd14449eaf77dc3d39

1 files changed, 2 insertions, 1 deletions

diff --git a/setup.cfg b/setup.cfg
index 2c3a5a9..e0510ae 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -35,9 +35,10 @@ console_scripts =
 
 [build_sphinx]
 builders = html,man
+all-files = 1
+warning-is-error = 1
 source-dir = doc/source
 build-dir = doc/build
-all_files = 1
 
 [upload_sphinx]
 upload-dir = doc/build/html