Bump flask-cors from 3.0.6 to 3.0.9

Bumps [flask-cors](https://github.com/corydolphin/flask-cors) from 3.0.6 to 3.0.9.
- [Release notes](https://github.com/corydolphin/flask-cors/releases)
- [Changelog](https://github.com/corydolphin/flask-cors/blob/master/CHANGELOG.md)
- [Commits](corydolphin/flask-cors@3.0.6...3.0.9)

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

Author: dependabot[bot]

requirements.txt

@@ -8,7 +8,7 @@ click==6.7
 teal==0.2.0a38
 ereuse-utils[naming, test, session, cli]==0.4.0b21
 Flask==1.0.2
-Flask-Cors==3.0.6
+Flask-Cors==3.0.9
 Flask-SQLAlchemy==2.3.2
 colorama==0.3.9
 colour==0.1.5