Bump bleach from 3.0.2 to 3.1.4

Bumps [bleach](https://github.com/mozilla/bleach) from 3.0.2 to 3.1.4.
- [Release notes](https://github.com/mozilla/bleach/releases)
- [Changelog](https://github.com/mozilla/bleach/blob/master/CHANGES)
- [Commits](mozilla/bleach@v3.0.2...v3.1.4)

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

requirements.txt

@@ -2,7 +2,7 @@ altgraph==0.16.1
 asteval==0.9.14
 attrs==19.1.0
 backcall==0.1.0
-bleach==3.0.2
+bleach==3.1.4
 bokeh==1.3.2
 certifi==2019.6.16
 Click==7.0