fix: bootstrap 4 alert scss toast hover style closes #661

src/lib/toastr-bs4-alert.scss

@@ -111,7 +111,7 @@
       opacity: 0.75;
     }
   }
-  .toast:hover {
+  .ngx-toastr:hover {
     box-shadow: 0 0 10px rgba(0, 0, 0, 0.15);
     opacity: 1;
     cursor: pointer;