Remove external link styles

govuk_frontend_toolkit is potentially removing external link styles in alphagov/govuk_frontend_toolkit#293 . If that happens then we’ll want to remove them from govuk_elements as well.

README.md

@@ -61,7 +61,7 @@ The `_govuk_elements.scss` partial shows which files are required.
     @import "conditionals";                           // Media query mixin
     @import "device-pixels";                          // Retina image mixin
     @import "grid_layout";                            // Basic grid layout mixin
-    @import "typography";                             // Core bold and heading mixins, also external links
+    @import "typography";                             // Core bold and heading mixins
     @import "shims";                                  // Inline block mixin, clearfix placeholder
 
     // Mixins to generate components (chunks of UI)

app/views/snippets/typography_links.html

@@ -6,9 +6,5 @@
   <a href="#">A 19px body copy link</a>. Fusce dapibus, tellus ac cursus commodo, tortor mauris condimentum nibh, ut fermentum massa justo sit amet risus.
 </p>
 
-<p>
-  <a href="#" rel="external">A 19px body copy external link.</a> Fusce dapibus, tellus ac cursus commodo, tortor mauris condimentum nibh, ut fermentum massa justo sit amet risus.
-</p>
-
 
-<a href="#" class="link-back">Back</a>
+<a href="#" class="link-back">Back</a>

public/sass/elements/_govuk-template-base.scss

@@ -124,21 +124,6 @@ a:active {
   color: $link-active-colour;
 }
 
-// External link styles
-a[rel="external"] {
-  @include external-link-default;
-  @include external-link-16;
-
-  @include media(tablet) {
-    @include external-link-19;
-  }
-}
-
-.external-link {
-  @include external-link-12-no-hover;
-  @include external-link-heading;
-}
-
 // Set focus styles
 a {
   // Allow RGBA here, this line has been copied from govuk_template