Bump bleach from 3.1.2 to 3.1.4

Bumps [bleach](https://github.com/mozilla/bleach) from 3.1.2 to 3.1.4.
- [Release notes](https://github.com/mozilla/bleach/releases)
- [Changelog](https://github.com/mozilla/bleach/blob/master/CHANGES)
- [Commits](mozilla/bleach@v3.1.2...v3.1.4)

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

requirements.txt

@@ -1,6 +1,6 @@
 alabaster==0.7.12
 Babel==2.7.0
-bleach==3.1.2
+bleach==3.1.4
 certifi==2019.9.11
 chardet==3.0.4
 colorama==0.4.1