stylesheets: merge print rules with the application stylesheet

- Having a separate stylesheet for print rules is not a best practice
  (it makes an extra network request)
- It makes migrating to Sprockets 4 easier

app/assets/stylesheets/application.scss

@@ -5,4 +5,3 @@
 // = require ./fonts
 // = require leaflet
 // = require_tree .
-// = stub ./print.scss

app/assets/stylesheets/print.scss

@@ -1,6 +1,7 @@
 @import "colors";
 @import "fonts";
 
+@media print {
   .new-header,
   .sub-header,
   footer {
@@ -61,3 +62,4 @@ th {
   .updated-at {
     display: none;
   }
+}

app/views/layouts/application.html.haml

@@ -20,7 +20,6 @@
     = preload_link_tag(asset_url("Muli-Bold.woff2"))
 
     = stylesheet_link_tag 'application', media: 'all'
-    = stylesheet_link_tag 'print', media: 'print'
 
     = Gon::Base.render_data(camel_case: true, init: true, nonce:  request.content_security_policy_nonce)
 

config/initializers/assets.rb

@@ -10,5 +10,6 @@ Rails.application.config.assets.paths << Rails.root.join('node_modules', '@reach
 Rails.application.config.assets.paths << Rails.root.join('node_modules', '@mapbox', 'mapbox-gl-draw', 'dist')
 
 # Precompile additional assets.
-# application.js, application.css, and all non-JS/CSS in app/assets folder are already added.
-Rails.application.config.assets.precompile += ['print.css']
+# application.js, application.css, and all non-JS/CSS in the app/assets
+# folder are already added.
+# Rails.application.config.assets.precompile += %w( admin.js admin.css )