update oauth docs, add on_failure config to initializer
update oauth docs, add on_failure config to initializer

leftathome/supermarket,dpnl87/supermarket,nellshamrell/supermarket,chef/supermarket,dpnl87/supermarket,chef/supermarket,dpnl87/supermarket,rafaelmagu/supermarket,dpnl87/supermarket,tas50/supermarket,chef/supermarket,leftathome/supermarket,nellshamrell/supermarket,rafaelmagu/supermarket,leftathome/supermarket,juliandunn/supermarket,jzohrab/supermarket,chef/supermarket,nellshamrell/supermarket,robbkidd/supermarket,rafaelmagu/supermarket,robbkidd/supermarket,nellshamrell/supermarket,juliandunn/supermarket,robbkidd/supermarket,tas50/supermarket,jzohrab/supermarket,tas50/supermarket,leftathome/supermarket,juliandunn/supermarket,rafaelmagu/supermarket,chef/supermarket,robbkidd/supermarket,jzohrab/supermarket,tas50/supermarket,jzohrab/supermarket,juliandunn/supermarket