[AIRFLOW-4900] Resolve incompatible version of Werkzeug (#5535)
[AIRFLOW-4900] Resolve incompatible version of Werkzeug (#5535)

* [AIRFLOW-4900] Resolve incompatible version of Werkzeug

Pin Werkzeug version to >= 0.15 as flask requirement needs it.

* Update setup.py

(cherry picked from commit 2b366934cdc20e8fb60b4b1e7b6c840a6708b258)

owlabs/incubator-airflow,owlabs/incubator-airflow,owlabs/incubator-airflow,owlabs/incubator-airflow