A Flask-based proxy adding Access-Control-Allow-Origin=* to all responses.

Usage: Start the proxy with $ python3 server.py. You can then access http://127.0.0.1:5000/<URL> for any URL and any HTTP method. The response content and return code will be forwarded.

Example: Access https://jsonplaceholder.typicode.com/posts with http://127.0.0.1:5000/https://jsonplaceholder.typicode.com/posts.