[Python] Updates python test framework to pytest (#4765)

* Switches python generators to use pytest, useNose CLI option added if to allow nose to be used instead

* Adds ensure-up-to-date changes

* Adds setup.cfg to python clients so we can configure nose when useNose=true

* Adds fix for python-aiohttp testing, adds files missing from ensure-up-to-date

samples/openapi3/server/petstore/python-flask/.gitignore

@@ -45,7 +45,9 @@ coverage.xml
 *,cover
 .hypothesis/
 venv/
+.venv/
 .python-version
+.pytest_cache
 
 # Translations
 *.mo

samples/openapi3/server/petstore/python-flask/requirements.txt

@@ -1,4 +1,7 @@
-connexion >= 2.0.2
+connexion >= 2.5.0; python_version>="3.6"
+connexion >= 2.3.0; python_version=="3.5"
+connexion >= 2.3.0; python_version=="3.4"
+connexion == 2.4.0; python_version<="2.7"
 swagger-ui-bundle >= 0.0.2
 python_dateutil >= 2.6.0
 setuptools >= 21.0.0

samples/openapi3/server/petstore/python-flask/test-requirements.txt

@@ -1,6 +1,4 @@
-flask_testing==0.6.1
-coverage>=4.0.3
-nose>=1.3.7
-pluggy>=0.3.1
-py>=1.4.31
-randomize>=0.13
+pytest~=4.6.7 # needed for python 2.7+3.4
+pytest-cov>=2.8.1
+pytest-randomly==1.2.3 # needed for python 2.7+3.4
+flask_testing==0.6.1

samples/openapi3/server/petstore/python-flask/tox.ini

@@ -6,5 +6,4 @@ deps=-r{toxinidir}/requirements.txt
      -r{toxinidir}/test-requirements.txt
 
 commands=
-   nosetests \
-      []
+   pytest --cov=openapi_server