Added data-project attribute to body tag.

app/views/layouts/application.html.haml

 !!! 5
 %html{ lang: "en"}
   = render "layouts/head"
-  %body{class: "#{user_application_theme}", 'data-page' => body_data_page}
+  %body{class: "#{user_application_theme}", 'data-page' => body_data_page, 'data-project' => "#{@project.path if @project}"}
     = Gon::Base.render_data
 
     -# Ideally this would be inside the head, but turbolinks only evaluates page-specific JS in the body.