Bump flask from 1.1.2 to 2.0.0

Bumps [flask](https://github.com/pallets/flask) from 1.1.2 to 2.0.0.
- [Release notes](https://github.com/pallets/flask/releases)
- [Changelog](https://github.com/pallets/flask/blob/main/CHANGES.rst)
- [Commits](pallets/flask@1.1.2...2.0.0)

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

requirements.txt

@@ -1,7 +1,7 @@
 bandit==1.7.0
 coverage==5.5
 coveralls==3.0.1
-Flask==1.1.2
+Flask==2.0.0
 Flask-SSLify==0.1.5
 Flask-Testing==0.8.1
 Flask-SeaSurf==0.3.0