Bump sphinx-rtd-theme from 0.4.2 to 0.4.3 (#13)

Bumps [sphinx-rtd-theme](https://github.com/rtfd/sphinx_rtd_theme) from 0.4.2 to 0.4.3.
- [Release notes](https://github.com/rtfd/sphinx_rtd_theme/releases)
- [Changelog](https://github.com/rtfd/sphinx_rtd_theme/blob/master/docs/changelog.rst)
- [Commits](readthedocs/sphinx_rtd_theme@0.4.2...0.4.3)

Signed-off-by: dependabot[bot] <support@dependabot.com>

requirementsDocs.txt

@@ -1,6 +1,6 @@
 sphinx==1.8.4
 sphinxcontrib-plantuml==0.14
 sphinxcontrib-ansibleautodoc==0.0.5
-sphinx_rtd_theme==0.4.2
+sphinx_rtd_theme==0.4.3
 PyYAML>=4.2b1
 m2r==0.2.1