Bump flask from 0.12 to 1.0

Bumps [flask](https://github.com/pallets/flask) from 0.12 to 1.0.
- [Release notes](https://github.com/pallets/flask/releases)
- [Changelog](https://github.com/pallets/flask/blob/master/CHANGES.rst)
- [Commits](https://github.com/pallets/flask/compare/0.12...1.0)

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

requirements.txt

@@ -1,6 +1,6 @@
 APScheduler==3.2.0
 werkzeug==0.11.15
-Flask==0.12
+Flask==1.0
 requests==2.20.0
 lxml==3.7.2
 PyExecJS==1.5.1