sphinxext: Resolve compatibility with Sphinx 4.x

This necessitates bumping the lowest version supported to avoid having
to maintain shims.

Change-Id: I6c324a5a7c2b7296a15aaa57fc8b98491099702c
Signed-off-by: Stephen Finucane <stephenfin@redhat.com>

doc/requirements.txt

@@ -1 +1 @@
-sphinx!=1.6.6,!=1.6.7,>=1.6.2,<4.0.0 # BSD
+sphinx>=3.0.0 # BSD

test-requirements.txt

@@ -1,6 +1,6 @@
 transaction
 pecan
-sphinx!=1.6.6,!=1.6.7,>=1.6.2,<4.0.0 # BSD
+sphinx>=3.0.0 # BSD
 Flask
 flask-restful
 nose

wsmeext/sphinxext.py

@@ -5,10 +5,13 @@ import sys
 from docutils.parsers.rst import Directive
 from docutils.parsers.rst import directives
 from sphinx import addnodes
-from sphinx.ext import autodoc
-from sphinx.domains.python import PyClasslike, PyClassmember
-from sphinx.domains import Domain, ObjType
 from sphinx.directives import ObjectDescription
+from sphinx.domains import Domain
+from sphinx.domains import ObjType
+from sphinx.domains.python import PyAttribute
+from sphinx.domains.python import PyClasslike
+from sphinx.domains.python import PyMethod
+from sphinx.ext import autodoc
 from sphinx.locale import _
 from sphinx.roles import XRefRole
 from sphinx.util.docfields import Field
@@ -153,7 +156,7 @@ class TypeDirective(PyClasslike):
         return ret
 
 
-class AttributeDirective(PyClassmember):
+class AttributeDirective(PyAttribute):
     doc_field_types = [
         Field('datatype', label=_('Type'), has_arg=False,
               names=('type', 'datatype'))
@@ -368,7 +371,7 @@ class ServiceDocumenter(autodoc.ClassDocumenter):
         return '/' + '/'.join(path)
 
 
-class FunctionDirective(PyClassmember):
+class FunctionDirective(PyMethod):
     name = 'function'
     objtype = 'function'
 
@@ -592,5 +595,5 @@ def setup(app):
     app.add_config_value('wsme_root', None, 'env')
     app.add_config_value('wsme_webpath', '/', 'env')
     app.add_config_value('wsme_protocols', ['restjson', 'restxml'], 'env')
-    app.add_javascript('toggle.js')
-    app.add_stylesheet('toggle.css')
+    app.add_js_file('toggle.js')
+    app.add_css_file('toggle.css')