refine form_for syntax for invitations form
refine form_for syntax for invitations form

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