Refactor: Remove unused progress code

Author: yourWaifu

lib/browser/progress.js

@@ -37,7 +37,7 @@ exports = module.exports = HTML;
 
 var statsTemplate =
   '<ul id="mocha-stats">' +
-  '<li class="progress-contain"><em>0</em>% <progress class="progress-element" id="progress-element" max="100" value="0" /></li>' +
+  '<li class="progress-contain"><em>0</em>% <progress class="progress-element" max="100" value="0" /></li>' +
   '<li class="passes"><a href="javascript:void(0);">passes:</a> <em>0</em></li>' +
   '<li class="failures"><a href="javascript:void(0);">failures:</a> <em>0</em></li>' +
   '<li class="duration">duration: <em>0</em>s</li>' +