[lib] werkzeug 0.15.5 was published
[lib] werkzeug 0.15.5 was published

- pytest-httpbin needs httpbin and httpbin needs werkzeug >= 0.14.1
- Python 3.8 needs werkzeug 0.15.5
- github vulnerable depedency suggests werkzeug >= 0.15.3

Change-Id: Ia84b2ea485d3cf47b92e878c7d6c4c0ed65dbcf8

wikimedia/pywikibot-core,PersianWikipedia/pywikibot-core,wikimedia/pywikibot-core