Bump flask-cors from 3.0.3 to 3.0.9

Bumps [flask-cors](https://github.com/corydolphin/flask-cors) from 3.0.3 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@3.0.3...3.0.9)

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

requirements.txt

@@ -13,7 +13,7 @@ docopt==0.6.2
 enum34==1.1.6
 flasgger==0.8.0
 Flask>1.0.0
-Flask-Cors==3.0.3
+Flask-Cors==3.0.9
 Flask-API==1.0
 Flask-Bcrypt==0.7.1
 Flask-Migrate==2.1.1