Added e2e test checking integration access

refs https://github.com/TryGhost/Team/issues/2790

- The Self-Serve Integration should only be accessible to the Owner and Admin user roles otherwise we risk accidental indirect increase in role permissions - Self-Serve Integration has permissions which editors/contributors don't have.

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

@@ -0,0 +1,32 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`Integrations API As Administrator Can't see Self-Serve or any other integration 1: [body] 1`] = `
+Object {
+  "errors": Array [
+    Object {
+      "code": null,
+      "context": "You do not have permission to browse integrations",
+      "details": null,
+      "ghostErrorCode": null,
+      "help": null,
+      "id": StringMatching /\\[a-f0-9\\]\\{8\\}-\\[a-f0-9\\]\\{4\\}-\\[a-f0-9\\]\\{4\\}-\\[a-f0-9\\]\\{4\\}-\\[a-f0-9\\]\\{12\\}/,
+      "message": "Permission error, cannot list integrations.",
+      "property": null,
+      "type": "NoPermissionError",
+    },
+  ],
+}
+`;
+
+exports[`Integrations API As Administrator Can't see Self-Serve or any other integration 2: [headers] 1`] = `
+Object {
+  "access-control-allow-origin": "http://127.0.0.1:2369",
+  "cache-control": "no-cache, private, no-store, must-revalidate, max-stale=0, post-check=0, pre-check=0",
+  "content-length": "280",
+  "content-type": "application/json; charset=utf-8",
+  "content-version": StringMatching /v\\\\d\\+\\\\\\.\\\\d\\+/,
+  "etag": StringMatching /\\(\\?:W\\\\/\\)\\?"\\(\\?:\\[ !#-\\\\x7E\\\\x80-\\\\xFF\\]\\*\\|\\\\r\\\\n\\[\\\\t \\]\\|\\\\\\\\\\.\\)\\*"/,
+  "vary": "Accept-Version, Origin, Accept-Encoding",
+  "x-powered-by": "Express",
+}
+`;

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

@@ -4,6 +4,8 @@ const supertest = require('supertest');
 const config = require('../../../core/shared/config');
 const testUtils = require('../../utils');
 const localUtils = require('./utils');
+const {agentProvider, fixtureManager, matchers} = require('../../utils/e2e-framework');
+const {anyEtag, anyErrorId, anyContentVersion} = matchers;
 
 describe('Integrations API', function () {
     let request;
@@ -350,4 +352,31 @@ describe('Integrations API', function () {
 
         editRes.body.errors[0].context.should.eql('Integration not found.');
     });
+
+    describe('As Administrator', function () {
+        let agent;
+
+        before(async function () {
+            agent = await agentProvider.getAdminAPIAgent();
+            await fixtureManager.init('users', 'integrations');
+            await agent.loginAsContributor();
+        });
+
+        it('Can\'t see Self-Serve or any other integration', async function () {
+            await agent
+                .get('integrations')
+                .matchHeaderSnapshot({
+                    'content-version': anyContentVersion,
+                    etag: anyEtag
+                })
+                .matchBodySnapshot({
+                    errors: [
+                        {
+                            id: anyErrorId
+                        }
+                    ]
+                })
+                .expectStatus(403);
+        });
+    });
 });