Add toast component interactions

Include boostrap toast component to communicate success
and error requests on the local user management page.

- Created BVToastMixin to share initialization options
- Used async/await pattern to make sure toasts are shown
  after asynchronous calls are complete
- Followed current AngularJS pattern of manual dismiss for
  error toast and automatic dismiss for success toast

Signed-off-by: Yoshie Muranaka <yoshiemuranaka@gmail.com>
Change-Id: I5d5c037b5f41781972106fb5e9a2096cc72c39ab
diff --git a/src/main.js b/src/main.js
index e32a56b..d80d201 100644
--- a/src/main.js
+++ b/src/main.js
@@ -21,7 +21,8 @@
   ModalPlugin,
   NavbarPlugin,
   NavPlugin,
-  TablePlugin
+  TablePlugin,
+  ToastPlugin
 } from 'bootstrap-vue';
 import Vuelidate from 'vuelidate';
 
@@ -52,6 +53,7 @@
 Vue.use(NavbarPlugin);
 Vue.use(NavPlugin);
 Vue.use(TablePlugin);
+Vue.use(ToastPlugin);
 Vue.use(Vuelidate);
 
 new Vue({