Log Message:
py-sphinx: updated to 1.8.4

Release 1.8.4:

Bugs fixed
* latex: no bold checkmark (✔) available.
* with the documentation language set to Chinese, English words could not
  be searched.
* LaTeX: user numfig_format is stripped of spaces and may cause
  build failure
* C++, fix hyperlinks for declarations involving east cv-qualifiers.
* C++, fix duplicate declaration error on function templates with constraints
  in the return type.
* C++, parse unary right fold expressions and binary fold expressions.
* pycode could not handle egg files on windows
* KeyError: 'DOCUTILSCONFIG' when running build
* LaTeX: PDF build broken by inclusion of image taller than page height
  in an admonition
* "make html" does not read and build "po" files in \ 
"locale" dir
* :scale: image option may break PDF build if image in an admonition
* LaTeX: modified PDF layout since September 2018 TeXLive update of
  :file:parskip.sty
* LaTeX: duplicated labels are generated for sections
* versionadded directive causes crash with Python 3.5.0
* autodoc: autodoc_mock_imports conflict with metaclass on Python 3.7
* texinfo: a section title . is not allowed