Bump twisted from 16.2.0 to 20.3.0

Bumps [twisted](https://github.com/twisted/twisted) from 16.2.0 to 20.3.0.
- [Release notes](https://github.com/twisted/twisted/releases)
- [Changelog](https://github.com/twisted/twisted/blob/trunk/NEWS.rst)
- [Commits](twisted/twisted@twisted-16.2.0...twisted-20.3.0)

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

Author: dependabot[bot]

requirements.txt

@@ -31,7 +31,7 @@ setuptools==49.0.0
 spooky==2.0.0
 sqlalchemy==1.1.7
 sshtunnel==0.1.3
-twisted==19.7.0
+twisted==20.3.0
 validators==0.12.0
 xmltodict==0.11.0
 pyYAML==5.3.1