Merge pull request #2741 from return42/fix-sphinx-theme

[fix] docutils v0.17 incompatibility to previeous v0.16

requirements-dev.txt

@@ -8,6 +8,7 @@ transifex-client==0.14.2
 selenium==3.141.0
 twine==3.4.1
 Pallets-Sphinx-Themes==1.2.3
+docutils==0.16
 Sphinx==3.5.3
 sphinx-issues==1.2.0
 sphinx-jinja==1.1.1