Python AIOHTTP server generator (#1470)

* Astract factory for generators based on connexion

* Add aiohttp server generator

* Fix flask tests

* Normalize python-flask folder names

samples/server/petstore/python-aiohttp/test_python3.sh

@@ -0,0 +1,32 @@
+#!/bin/bash
+
+REQUIREMENTS_FILE=requirements.txt
+TEST_REQUIREMENTS_FILE=test-requirements.txt
+REQUIREMENTS_OUT=requirements.txt.log
+SETUP_OUT=*.egg-info
+VENV=.venv
+DEACTIVE=false
+
+export LC_ALL=en_US.UTF-8
+export LANG=en_US.UTF-8
+
+### set virtualenv
+if [ -z "$VIRTUAL_ENV" ]; then
+	virtualenv $VENV --no-site-packages --always-copy --python python3
+		source $VENV/bin/activate
+    DEACTIVE=true
+fi
+
+### install dependencies
+pip install -r $REQUIREMENTS_FILE -r $TEST_REQUIREMENTS_FILE | tee -a $REQUIREMENTS_OUT
+
+### run tests
+pytest || exit 1
+
+### static analysis of code
+flake8 --show-source petstore_api/
+
+### deactivate virtualenv
+if [ $DEACTIVE == true ]; then
+    deactivate
+fi