FIX: Email Styles were evaluated out of order

`yield` puts the content in the template right away unless explicitly
`capture`'d.

app/helpers/email_helper.rb

@@ -26,7 +26,7 @@ module EmailHelper
   end
 
   def email_html_template
-    EmailStyle.new.html.sub('%{email_content}', yield).html_safe
+    EmailStyle.new.html.sub('%{email_content}', capture { yield }).html_safe
   end
 
   protected