Refactor tab tests

lms/templates/courseware/welcome-back.html

 <%!
 from django.utils.translation import ugettext as _ 
-import waffle 
+import waffle
 %>
 
 <h2>${chapter_module.display_name_with_default}</h2>

lms/templates/widgets/segment-io.html

@@ -5,7 +5,6 @@
 
 <% active_flags = " + ".join(waffle.get_flags(request)) %>
 
-<!-- <script src="${ reverse('wafflejs') }"></script> -->
 <script type="text/javascript">
   var analytics=analytics||[];analytics.load=function(e){var t=document.createElement("script");t.type="text/javascript",t.async=!0,t.src=("https:"===document.location.protocol?"https://":"http://")+"d2dq2ahtl5zl1z.cloudfront.net/analytics.js/v1/"+e+"/analytics.min.js";var n=document.getElementsByTagName("script")[0];n.parentNode.insertBefore(t,n);var r=function(e){return function(){analytics.push([e].concat(Array.prototype.slice.call(arguments,0)))}},i=["identify","track","trackLink","trackForm","trackClick","trackSubmit","pageview","ab","alias","ready"];for(var s=0;s<i.length;s++)analytics[i[s]]=r(i[s])};
   analytics.load("${ settings.SEGMENT_IO_LMS_KEY }");