Bump flask-static-digest from 0.1.3 to 0.1.4 in /requirements

Bumps [flask-static-digest](https://github.com/nickjj/flask-static-digest) from 0.1.3 to 0.1.4.
- [Release notes](https://github.com/nickjj/flask-static-digest/releases)
- [Changelog](https://github.com/nickjj/flask-static-digest/blob/master/CHANGELOG.md)
- [Commits](nickjj/flask-static-digest@v0.1.3...v0.1.4)

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

Author: dependabot[bot]

requirements/prod.txt

@@ -24,7 +24,7 @@ gunicorn>=19.9.0
 supervisor==4.2.1
 
 # Flask Static Digest
-Flask-Static-Digest==0.1.3
+Flask-Static-Digest==0.1.4
 
 # Auth
 Flask-Login==0.5.0