Stroked through text is now displayed correctly

Closes #87

app/views/events/show.html.haml

@@ -91,7 +91,7 @@
 %h3= t '.description'
 .description
   = description sanitize @event.description,
-    tags: %w(p h1 h2 h3 h4 br table tr th td ul ol li a strong b em i img sub sup),
+    tags: %w(p h1 h2 h3 h4 br table tr th td ul ol li a strong b em i img sub sup span),
     attributes: %w(href src width height style title)
 
 %h3

app/views/orgas/show.html.haml

@@ -75,7 +75,7 @@
 %h3= t '.description'
 .description
   = description sanitize @orga.description,
-    tags: %w(p h1 h2 h3 h4 br table tr th td ul ol li a strong b em i img sub sup),
+    tags: %w(p h1 h2 h3 h4 br table tr th td ul ol li a strong b em i img sub sup span),
     attributes: %w(href src width height style title)
 
 %dl