- update: Bootstrap version to v4.0.0-beta.2

- update: vue-chartjs version to 3.0.0
- refactor: Remove old SCSS variables
- refactor: Breadcrumb Menu styles
- fix: External links issue
- fix: Mobile sidebar-nav height issue

Vue_Starter/scss/bootstrap/mixins/_badge.scss

@@ -1,10 +1,10 @@
 @mixin badge-variant($bg) {
-  @include color-yiq($bg);
+  color: color-yiq($bg);
   background-color: $bg;
 
   &[href] {
     @include hover-focus {
-      @include color-yiq($bg);
+      color: color-yiq($bg);
       text-decoration: none;
       background-color: darken($bg, 10%);
     }