Add a test to ensure the Apache bug doesn't come up again.

features/highlighting.feature

@@ -0,0 +1,33 @@
+Feature: Syntax Highlighting
+  As a hacker who likes to blog
+  I want to share code snippets in my blog
+  And make them pretty for all the world to see
+
+  Scenario: highlighting an apache configuration
+    Given I have an "index.html" file with content:
+      """
+      ---
+      ---
+
+      {% highlight apache %}
+      RewriteEngine On
+      RewriteCond %{REQUEST_FILENAME} !-f
+      RewriteCond %{REQUEST_FILENAME} !-d
+      RewriteRule ^(.*)$ index.php [QSA,L]
+      {% endhighlight %}
+
+      ```apache
+      RewriteEngine On
+      RewriteCond %{REQUEST_FILENAME} !-f
+      RewriteCond %{REQUEST_FILENAME} !-d
+      RewriteRule ^(.*)$ index.php [QSA,L]
+      ```
+      """
+    And I have a "_config.yml" file with content:
+      """
+      kramdown:
+        input: GFM
+      """
+    When I run jekyll build
+    Then I should get a zero exit-status
+    And I should see "<span class="nc">RewriteCond</span>" in "_site/index.html"