docs - Set pbr 'warnerrors' option for doc build

By setting this pbr option in setup.cfg, the doc build will fail in case
of any warnings or errors occur during the build process.

Closes-Bug: #1351350

Change-Id: Id4858062d2aaa4c2fe5b597e40e4e8947f544a4d

doc/source/conf.py

@@ -194,7 +194,7 @@ man_pages = [
 # Add any paths that contain custom static files (such as style sheets) here,
 # relative to this directory. They are copied after the builtin static files,
 # so a file named "default.css" will overwrite the builtin "default.css".
-html_static_path = ['_static']
+#html_static_path = ['_static']
 
 # If not '', a 'Last updated on:' timestamp is inserted at every page bottom,
 # using the given strftime format.

doc/source/index.rst

@@ -48,6 +48,7 @@ Developer Docs
 
    devref/index
    man/index
+   api/autoindex
 
 API Extensions
 ==============

setup.cfg

@@ -166,3 +166,4 @@ universal = 1
 
 [pbr]
 autodoc_index_modules = 1
+warnerrors = true