Merge pull request rackspace-cookbooks#42 from restorando/master

Fix reporting exceptions with libyajl2

files/default/slack_handler_webhook.rb

@@ -106,7 +106,7 @@ def request_body(message, text_attachment)
       body[:icon_emoji] = @icon_emoji
     end
     body[:channel] = @channel if @channel
-    body[:attachments] = [{ text: text_attachment }] unless text_attachment.nil?
+    body[:attachments] = [{ text: text_attachment.to_s }] unless text_attachment.nil?
     body.to_json
   end
 end