callAPI is an internal function to run an API request.
callAPI(url, token, api =NULL)
Arguments
url: URL of API request
token: Either a temporary access token created at https://developers.facebook.com/tools/explorer or the OAuth token created with fbOAuth. It needs to have extended permissions in order to successfully post to the Facebook profile.
api: API version. e.g. "v2.8". NULL is the default.