Don't allow style attributes in inline HTML

CHANGELOG

 Please view this file on the master branch, on stable branches it's out of date.
 
 v 7.10.0 (unreleased)
+  - Allow HTML tags in Markdown input
 
 v 7.9.0 (unreleased)
   - Add HipChat integration documentation (Stan Hu)

lib/gitlab/markdown.rb

@@ -88,7 +88,7 @@ module Gitlab
       ]
 
       whitelist = HTML::Pipeline::SanitizationFilter::WHITELIST
-      whitelist[:attributes][:all].push('class', 'id', 'style')
+      whitelist[:attributes][:all].push('class', 'id')
 
       # Remove the rel attribute that the sanitize gem adds, and remove the
       # href attribute if it contains inline javascript