Bump flask from 0.10 to 1.0 (#302)

Bumps [flask](https://github.com/pallets/flask) from 0.10 to 1.0.
- [Release notes](https://github.com/pallets/flask/releases)
- [Changelog](https://github.com/pallets/flask/blob/master/CHANGES.rst)
- [Commits](pallets/flask@0.10...1.0)

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

requirements.txt

@@ -5,7 +5,7 @@ Flask-Assets==2.0
 Flask-DebugToolbar==0.7.1
 Flask-SeaSurf==0.1.13
 Flask-Cors==2.0.1
-Flask==0.11
+Flask==1.0
 gevent==20.6.2
 gunicorn>=17.5,<=19.4.1
 hiredis==0.1.4