Support for expiring access tokens

[pbstriker38]

When expiring access tokens are enabled a refresh_token and refresh_token_expires_in are returned. Can the refresh_token_expires_in be added to the credentials hash.

https://docs.github.com/en/developers/apps/building-github-apps/identifying-and-authorizing-users-for-github-apps#response

{
  "access_token": "ghu_16C7e42F292c6912E7710c838347Ae178B4a",
  "expires_in": 28800,
  "refresh_token": "ghr_1B4a2e77838347a7E420ce178F2E7c6912E169246c34E1ccbF66C46812d16D5B1A9Dc86A1498",
  "refresh_token_expires_in": 15811200,
  "scope": "",
  "token_type": "bearer"
}