Bring in Jinja and Sass for checkboxes component

app/assets/stylesheets/govuk-frontend/_all.scss

@@ -26,6 +26,7 @@ $govuk-assets-path: "/static/";
 @import 'components/button/_button';
 @import 'components/details/_details';
 @import 'components/radios/_radios';
+@import 'components/checkboxes/_checkboxes';
 
 @import "utilities/all";
 @import "overrides/all";

gulpfile.js

@@ -65,7 +65,12 @@ const copy = {
         'footer',
         'back-link',
         'details',
-        'button'
+        'button',
+        'error-message',
+        'fieldset',
+        'hint',
+        'label',
+        'checkboxes'
       ];
       let done = 0;