Bump redis from 3.5.2 to 3.5.3

Bumps [redis](https://github.com/andymccurdy/redis-py) from 3.5.2 to 3.5.3.
- [Release notes](https://github.com/andymccurdy/redis-py/releases)
- [Changelog](https://github.com/andymccurdy/redis-py/blob/master/CHANGES)
- [Commits](https://github.com/andymccurdy/redis-py/compare/3.5.2...3.5.3)

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

setup.py

@@ -40,7 +40,7 @@ setup(
         'Flask-Caching==1.8.0',
         'geopy==1.22.0',
         'celery==4.4.2',
-        'redis==3.5.2',
+        'redis==3.5.3',
         'aerofiles==1.0.0',
         'geoalchemy2==0.8.3',
         'shapely==1.7.0',