{
  "access_token": "accesstoken",
  "expires_in": "28800",
  "refresh_token": "r1.refreshme",
  "refresh_token_expires_in": "15811200",
  "scope": "",
  "token_type": "bearer" POST /login/oauth/access_token HTTP/1.1
Host: github.com

grant_type=refresh_token
refresh_token=r1.refreshme
&client_id=5566778899
&client_secret=5566778899