Bump bleach from 3.1.1 to 3.1.4

Bumps [bleach](https://github.com/mozilla/bleach) from 3.1.1 to 3.1.4.
- [Release notes](https://github.com/mozilla/bleach/releases)
- [Changelog](https://github.com/mozilla/bleach/blob/master/CHANGES)
- [Commits](mozilla/bleach@v3.1.1...v3.1.4)

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

Author: dependabot[bot]

requirements.txt

@@ -2,7 +2,7 @@ appdirs==1.4.3
 atomicwrites==1.3.0
 attrs==19.1.0
 black==19.3b0
-bleach==3.1.1
+bleach==3.1.4
 certifi==2019.6.16
 chardet==3.0.4
 Click==7.0