Fixed custom integrations tests

ghost/admin/mirage/config/integrations.js

@@ -9,6 +9,9 @@ export default function mockIntegrations(server) {
         let body = JSON.parse(requestBody);
         let [params] = body.integrations;
 
+        // all integrations created via the API have a type of 'custom'
+        params.type = 'custom';
+
         if (!params.name) {
             return new Response(422, {}, {errors: [{
                 errorType: 'ValidationError',

ghost/admin/mirage/factories/integration.js

@@ -6,6 +6,7 @@ export default Factory.extend({
     slug() { return this.name.toLowerCase().replace(' ', '-'); },
     description: null,
     iconImage: null,
+    type: 'custom',
 
     createdAt() { return moment.utc().format(); },
     createdBy: 1,