- 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/core/_breadcrumb-menu.scss

@@ -1,19 +1,19 @@
 .breadcrumb-menu {
-  position: absolute;
-  top: 0;
-  right: $breadcrumb-padding-x;
+  margin-left: auto;
 
   &::before {
     display: none;
   }
 
-  .btn {
-    padding-top: $breadcrumb-padding-y;
-    padding-bottom: $breadcrumb-padding-y;
+  .btn-group {
+    vertical-align: top;
   }
 
   .btn {
+    padding: 0 $input-btn-padding-x;
     color: $text-muted;
+    vertical-align: top;
+    border: 0;
 
     &:hover, &.active {
       color: $body-color;

Vue_Starter/scss/core/_breadcrumb.scss

@@ -1,6 +1,4 @@
 .breadcrumb {
   position: relative;
-  margin: $breadcrumb-margin;
-
   @include borders($breadcrumb-borders);
 }

Vue_Starter/scss/core/_layout.scss

@@ -349,7 +349,7 @@ app-root {
     .sidebar-nav,
     .nav {
       width: $mobile-sidebar-width !important;
-      height: calc(100vh - #{$navbar-height});
+      min-height: calc(100vh - #{$navbar-height});
     }
 
     .sidebar-minimizer {

Vue_Starter/scss/core/_variables.scss

@@ -176,8 +176,6 @@ $top-nav-active-bg:                   theme-color("primary") !default;
 $top-nav-height:                      $navbar-height - 15px !default;
 
 // Breadcrumb
-
-$breadcrumb-margin:                   0 0 (1.5 * $spacer) 0 !default;
 $breadcrumb-borders: (
   bottom: (
     size:                             1px,