[ADD] customer information un pos summary display

src/components/SummaryDisplay.vue

@@ -1,6 +1,7 @@
 <template lang="pug">
     .summary
         h2 {{ getTotal() }}
+        h3 {{ customer.name }}
 </template>
 
 <script>
@@ -8,7 +9,8 @@
 
     export default {
         computed: mapGetters({
-            total: 'getTotal'
+            total: 'getTotal',
+            customer: 'getSelectedCustomer'
         }),
         methods: {
             getTotal() {