python connexion Werzeug swagger tests fails

tox tests fail

ImportError: cannot import name 'FileStorage'

I see a lot of references to issues between versions but was not able to resolve what is the right combo of pinning what with what to make the tests not fail. 

process

1) export server stub for python-flask   #spec is 3.0.0

2) mkdir testdir && cd testdir

3) python3 -m venv env

4) source env/bin/activate

5) unzip python-flask.zip file from export in #1 into testdir

6) pip install -r requirements.txt   #aka as supplied by swaggerhub export, you'd think these would be right?

7) pip install tox

8) change tox.ini to py36  #cuz that's what I'm on

9) tox

results:  ImportError: cannot import name 'FileStorage'

Obviously issues with connexion, wertzeug, etc.

Tried pinning to several combo's of wertzeug, connexion etc, but didn't end up with anything I thought worked nor would be stable.