app/views/new_activity_mailer/new_activity.html.haml
%h2 New Activity - #{@from_user.username}
%p
Dear #{@to_user.username},
%p
Just thought you might like to know,
#{@from_user.username} has #{@action_statement}.
%p
= link_to 'Go check it out', path_to_notifiable(@notifiable)
%p
.center{style: "text-align: center;"}
= image_tag attachments['bullhorn.png'].url, width: '200'
%p
= link_to "Change your notification settings", edit_notifications_url