gradle clean build;
java -jar build/output/HTTPCacheService-1.0.jar 8080
use http method POST to set data and use GET to get data
EX:
1. key = GOGOGO, value = POWERRANGER
for set data, send request to http://localhost:8080/GOGOGO, use method `POST` and body `POWERRANGER`
for get data, send request to http://localhost:8080/GOGOGO, use method `GET` and it'll return `POWERRANGER` on body
for delete data, send request to http://localhost:8080/GOGOGO, use method `DELETE`