Allow flash messages to appear a second time

lib/assets/javascripts/flash.js

@@ -40,10 +40,16 @@ $( document ).on('turbolinks:load', function() {
           container.animation = setTimeout(hide, DURATION);
       }
 
-      button.on('click', function () {
-        clearTimeout(container.animation);
-        hide();
-      });
+      // This will be fired by Bootstrap automatically
+      container.on('close.bs.alert', function (e) {
+        // Did the user click on the on the button to close?
+        if (e.target instanceof Element || e.target instanceof HTMLElement) {
+          clearTimeout(container.animation);
+          hide();
+        }
+        // We need to stop event propagation here. Otherwise, Bootstrap would remove the DOM element
+        e.preventDefault();
+      })
     });
   };