github API request

Tasks completed

1. Added the necessary API endpoint.
2. Added docker-compose and dockerfile. Server should start just with "docker-compose up" at localhost:3000
3. Added some sample integration tests for routes and a unit test for helper
4. Added cache support for faster performance

Route

get github data : POST req => localhost:3000/getGithubData/:page default values for body : { per_page = 1, sort = "stars", order = "desc", date = "2019-01-10", page = 1, }