Always render "browser not supported" alert and disable it for supported browsers

app/assets/javascripts/editor.js

@@ -16,9 +16,8 @@ $(document).on('turbolinks:load', function() {
 
   if ($('#editor').isPresent() && CodeOceanEditor) {
     if (CodeOceanEditor.isBrowserSupported()) {
+      $('#alert').hide();
       CodeOceanEditor.initializeEverything();
-    } else {
-      $('#alert').show();
     }
   }
 });

app/assets/javascripts/editor/editor.js.erb

@@ -418,7 +418,8 @@ configureEditors: function () {
 
   isBrowserSupported: function () {
     //  websockets are used for run, score and test
-    return Modernizr.websockets;
+    // Also exclude IE and IE 11
+    return Modernizr.websockets && window.navigator.userAgent.indexOf("MSIE") <= 0 && !navigator.userAgent.match(/Trident\/7\./);
   },
 
   populateCard: function (card, result, index) {
@@ -723,7 +724,7 @@ configureEditors: function () {
                                         type: 'POST',
                                         url: $('#editor').data('intervention-save-url')
                                     });
-                                };
+                                }
                             }
                         }
                     }, delta);

app/assets/stylesheets/editor.css.scss

@@ -31,7 +31,7 @@ button i.fa-spin {
   vertical-align: bottom;
 }
 
-#alert, #development-environment {
+#development-environment {
   display: none;
 }