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] <[email protected]>

Author: dependabot[bot]

dev.requirements.txt

@@ -1,7 +1,7 @@
 alabaster==0.7.12
 appdirs==1.4.3
 Babel==2.8.0
-bleach==3.1.2
+bleach==3.1.4
 certifi==2019.11.28
 cffi==1.14.0
 chardet==3.0.4