Added e2e test for bulk member deletion (#15730)

ref https://github.com/TryGhost/Team/issues/1446

- tests the `delete` api endpoint method for deleting a bulk set of members.

ghost/core/test/e2e-api/admin/__snapshots__/members.test.js.snap

@@ -455,6 +455,19 @@ Object {
 }
 `;
 
+exports[`Members API Bulk operations Can bulk delete members 1: [body] 1`] = `
+Object {
+  "meta": Object {
+    "errors": Array [],
+    "stats": Object {
+      "successful": 8,
+      "unsuccessful": 0,
+    },
+    "unsuccessfulIds": Array [],
+  },
+}
+`;
+
 exports[`Members API Bulk operations Can bulk unsubscribe members with deprecated subscribed filter (actual) 1: [body] 1`] = `
 Object {
   "bulk": Object {

ghost/core/test/e2e-api/admin/members.test.js

@@ -2828,4 +2828,20 @@ describe('Members API Bulk operations', function () {
         const updatedModel2 = await models.Member.findOne({id: member2.id}, {withRelated: 'labels'});
         should(updatedModel2.relations.labels.models.map(m => m.id)).match([firstId, secondId]);
     });
+
+    it('Can bulk delete members', async function () {
+        await agent
+            .delete('/members?all=true')
+            .expectStatus(200)
+            .matchBodySnapshot({
+                meta: {
+                    stats: {
+                        successful: 8,
+                        unsuccessful: 0
+                    },
+                    unsuccessfulIds: [],
+                    errors: []
+                }
+            });
+    });
 });