Create a server listening at port 8080, with the following API:
Response format: JSON like {"status":<status_code>,"body":"<response_body>"}
For example, successful response: {"status":"OK", "body":"Hello World"} error response: {"status":"Error", "body":"Method not supported"}
HTTP GET:
/api - returns the list of supported methods
/api/ping - returns the string "pong"
/api/set?key=&value= - sets a string value to a given string key
/api/get?key= - returns the value saved at the key or an empty string if the value has not been set
/api/rpush?key=&value= - adds a value to the end of a list
/api/rpop?key= - returns the value from the end of the list
/api/llen?key= - returns the length of the list
any other url - returns the string "Method not supported"