Doc: Bump sphinx. (GH-10676)

.azure-pipelines/docs-steps.yml

@@ -12,7 +12,7 @@ steps:
   inputs:
     versionSpec: '>=3.6'
 
-- script: python -m pip install sphinx==1.8.1 blurb python-docs-theme
+- script: python -m pip install sphinx==1.8.2 blurb python-docs-theme
   displayName: 'Install build dependencies'
 
 - ${{ if ne(parameters.latex, 'true') }}:

.travis.yml

@@ -54,7 +54,7 @@ matrix:
         # Sphinx is pinned so that new versions that introduce new warnings won't suddenly cause build failures.
         # (Updating the version is fine as long as no warnings are raised by doing so.)
         # The theme used by the docs is stored separately, so we need to install that as well.
-        - python -m pip install sphinx==1.8.1 blurb python-docs-theme
+        - python -m pip install sphinx==1.8.2 blurb python-docs-theme
       script:
         - make check suspicious html SPHINXOPTS="-q -W -j4"
     - os: osx