Add example

examples/helloworld/hello.py

@@ -0,0 +1,12 @@
+#!/usr/bin/env python3
+
+import connexion
+
+
+def post_greeting(name: str) -> str:
+    return 'Hello {name}'.format(name=name)
+
+if __name__ == '__main__':
+    app = connexion.App(__name__, 9090, specification_dir='swagger/')
+    app.add_api('helloworld-api.yaml')
+    app.run()