Make it possible to run upstream tests

- Do not use readthedocs-sphinx-ext, it is not packaged.
- Point to local version of sphinx_rtd_theme.

Gbp-Pq: Name tests-configuration.patch

tests/util.py

@@ -32,9 +32,7 @@ def build(root, builder='html', **kwargs):
 
     confoverrides = kwargs.pop('confoverrides', {})
     confoverrides['html_theme'] = 'sphinx_rtd_theme'
-    extensions = confoverrides.get('extensions', [])
-    extensions.append('readthedocs_ext.readthedocs')
-    confoverrides['extensions'] = extensions
+    confoverrides['html_theme_path'] = [os.path.abspath('../../..')]
     kwargs['confoverrides'] = confoverrides
 
     try:
@@ -54,7 +52,6 @@ def build(root, builder='html', **kwargs):
 
 
 def build_all(root, **kwargs):
-    for builder in ['html', 'singlehtml', 'readthedocs', 'readthedocsdirhtml',
-                    'readthedocssinglehtml', 'readthedocssinglehtmllocalmedia']:
+    for builder in ['html', 'singlehtml']:
         with build(root, builder, **kwargs) as ret:
             yield ret