Add python-experimental-openapiv3-sample (#4992)

Add python-experimental-openapiv3-sample

Add missing files for the Python samples

Add python-experimental-petstore.bat for openapi v3

Add python-experimental samples openapi v3

Add python-experimental samples openapi v3

Add python-experimental samples openapi v3. Address review comments

add missing files for test purpose

fix python formatting issues

fix python formatting issues

fix python formatting issues

Fix unit tests

fix python formatting issues

fix python formatting issues

fix python formatting issues

fix 'line too long' pep8 error

address PR comments for pep8 'line too long' problem

regenerate samples

execute samples scripts

dummy commit to retrigger circleci

Revert dummy commit, it didn't help.

samples/openapi3/client/petstore/python-experimental/test_python2.sh

@@ -0,0 +1,33 @@
+#!/bin/bash
+
+REQUIREMENTS_FILE=dev-requirements.txt
+REQUIREMENTS_OUT=dev-requirements.txt.log
+SETUP_OUT=*.egg-info
+VENV=venv
+DEACTIVE=false
+
+export LC_ALL=en_US.UTF-8
+export LANG=en_US.UTF-8
+PYTHONPATH="$(which python)"
+
+### set virtualenv
+if [ -z "$VIRTUAL_ENV" ]; then
+		virtualenv $VENV --python=$PYTHONPATH --no-site-packages --always-copy
+		source $VENV/bin/activate
+    DEACTIVE=true
+fi
+
+### install dependencies
+pip install -r $REQUIREMENTS_FILE | tee -a $REQUIREMENTS_OUT
+
+### run tests
+tox -e py27 || exit 1
+
+### static analysis of code
+flake8 --show-source petstore_api/
+
+### deactivate virtualenv
+#if [ $DEACTIVE == true ]; then
+#    deactivate
+#fi
+