Compile all assets from roots

application.rb

# Precompile all JS/CSS in root of app/assets/stylesheets and app/assets/javascripts
config.assets.precompile +=
  Dir[::Rails.root.join('app/assets/*/*.{js,css,coffee,sass,scss}*')].
  map { |i| File.basename(i).sub(/(\.js)?\.coffee$/, '.js') }.
  map { |i| File.basename(i).sub(/(\.css)?\.(sass|scss)$/, '.css') }.
  reject { |i| i =~ /^application\.(js|css)$/ }