This function authenticates and creates a token for LinkedIn's API REST
li_auth(app_name = NA, client_id = NA, client_secret = NA)Character. Your App's given name
Character. Your App's client ID
Character. Your App's client secret
Other Connections: bring_api,
db_download, db_upload,
f1_contacts, geoAddress,
queryDW, queryDummy,
queryProduc,
typeform_download
Other Social Networks: get_tweets,
li_profile