- Add Facebook id to store Facebook id.

…no friends, that is not issue in this case)

- Change property's name.

* feature/improve_test_case:
  Change name.
  Fix test for find.
  - Fix code style. - Change property's name.
  Fix syntax.
  Map api response to our model's format manually.
  Add test to ensure fetch friends success. (However, some people have no friends, that is not issue in this case)
  Prepare friends data at before to fit language mean.
  Change global property's name.
  - Fix code style. - Add Facebook id to store Facebook id.