Merge pull request plotly#4778 from edg2s/patch-1

notifier: Use full font stack as elsewhere

src/css/_notifier.scss

@@ -1,5 +1,5 @@
 .plotly-notifier {
-    font-family: 'Open Sans'; // Because not all contexts have this specified.
+    font-family: 'Open Sans', verdana, arial, sans-serif; // Because not all contexts have this specified.
     position: fixed;
     top: 50px;
     right: 20px;