osem/app/views/devise/shared/_openid.html.haml

.btn-group.btn-group-lg
  - omniauth_configured.each do |provider|
    = link_to user_omniauth_authorize_path(provider),
                                      class: "btn btn-success btn-lg",
                                      id: "omniauth-#{provider}",
                                      title: "Your #{provider} login" do
      %i{:class => "fa fa-#{provider}"}