Bump flask-cors from 3.0.2 to 3.0.6

Bumps [flask-cors](https://github.com/corydolphin/flask-cors) from 3.0.2 to 3.0.6.
- [Release notes](https://github.com/corydolphin/flask-cors/releases)
- [Changelog](https://github.com/corydolphin/flask-cors/blob/master/CHANGELOG.md)
- [Commits](corydolphin/flask-cors@3.0.2...3.0.6)

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

setup.py

@@ -47,7 +47,7 @@
         'enum34 >= 1.1.6',
         'future',
         'flask == 0.12',
-        'flask-cors == 3.0.2',
+        'flask-cors ==3.0.6',
         'gunicorn >= 19.7.1',
         'numpy >= 1.11, < 1.15',
         'psutil == 5.4.6',