unfollowUser method
Implementation
Future<SXTuple1<IGUserGraphStatus>> unfollowUser(String userId) async {
final body = {
"_csrftoken": _csrftoken,
"_uuid": _deviceId,
"_uid": _userId,
"user_id": userId
};
return (await _apiNet.postSignedJson("/friendships/destroy/$userId", body,
action: IGAPIAction.UserGraphUnfollow))
.tuple1();
}