Bump flask from 0.12.2 to 1.0

Bumps [flask](https://github.com/pallets/flask) from 0.12.2 to 1.0.
- [Release notes](https://github.com/pallets/flask/releases)
- [Changelog](https://github.com/pallets/flask/blob/master/CHANGES.rst)
- [Commits](pallets/flask@0.12.2...1.0)

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

Author: dependabot[bot]

requirements.txt

@@ -88,7 +88,7 @@ click==6.7
 colorlog==3.1.4
 cryptography==2.3
 entrypoints==0.2.3
-Flask==0.12.2
+Flask==1.0
 Flask-Cors==3.0.2
 Flask-Login==0.4.0
 flask-marshmallow==0.7.0