feat: Customers resource.

server/src/models/Customer.js

@@ -0,0 +1,11 @@
+import { Model } from 'objection';
+import TenantModel from '@/models/TenantModel';
+
+export default class Customer extends TenantModel {
+  /**
+   * Table name
+   */
+  static get tableName() {
+    return 'customers';
+  }
+}