doc: enable warning-is-error and fix warnings

A small workaround is required for a specific parameter (see the
inline comment).

Change-Id: I1eac60cc8ca89a12dd568f5a12f70fdab9b76b62

doc/source/conf.py

@@ -142,7 +142,7 @@ html_title = 'Sahara Client'
 # 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.

saharaclient/api/images.py

@@ -48,9 +48,11 @@ class ImageManager(base.ResourceManager):
     def update_tags(self, image_id, new_tags):
         """Update an Image tags.
 
-        :param list new_tags: list of tags that will replace currently
-                              assigned tags
+        :param new_tags: list of tags that will replace currently
+                              assigned  tags
         """
+        # Do not add :param list in the docstring above until this is solved:
+        # https://github.com/sphinx-doc/sphinx/issues/2549
         old_image = self.get(image_id)
 
         old_tags = frozenset(old_image.tags)

setup.cfg

@@ -96,6 +96,7 @@ openstack.data_processing.v1 =
 all_files = 1
 build-dir = doc/build
 source-dir = doc/source
+warning-is-error = 1
 
 [wheel]
 universal = 1