Added basic test coverage for the token service

refs https://github.com/TryGhost/Team/issues/1640

- This is groundwork before fixing the referenced bug

ghost/members-api/test/unit/lib/services/token.test.js

@@ -0,0 +1,30 @@
+const assert = require('assert');
+const TokenService = require('../../../../lib/services/token');
+
+describe('TokenService', function () {
+    let tokenService;
+
+    before(function () {
+        const privateKey = '-----BEGIN RSA PRIVATE KEY-----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\na4/tLo88gWEfcow6WQ==\n-----END RSA PRIVATE KEY-----\n';
+        const publicKey = '-----BEGIN RSA PUBLIC KEY-----\nMIGJAoGBAJ5ruiuI2gWDGdj8mAUOk1GXEsxUhql+gxBMIkxaQf2kNigCr/wYXqrTJN2fn4BL\ntMZqwKOA0ZbqaIRsEMFpDLyFLyFaqFpEpjpLLz/XUrIALzLlyz5Bbh0VjYm+dc7pSkQVpO0d\nHugC1NJkn0P2L8U37bACg7/jX3ct6iqrDV0nAgMBAAE=\n-----END RSA PUBLIC KEY-----\n';
+        const issuer = 'http://127.0.0.1:2369/members/api';
+
+        tokenService = new TokenService({
+            privateKey,
+            publicKey,
+            issuer
+        });
+    });
+
+    describe('encodeIdentityToken', function () {
+        it('can encode a token and decode it afterwards', async function () {
+            const token = await tokenService.encodeIdentityToken({sub: 'member@example.com'});
+            const decodedToken = await tokenService.decodeToken(token);
+
+            assert.deepEqual(Object.keys(decodedToken), ['sub', 'kid', 'iat', 'exp', 'aud', 'iss']);
+            assert.equal(decodedToken.aud, 'http://127.0.0.1:2369/members/api');
+            assert.equal(decodedToken.iss, 'http://127.0.0.1:2369/members/api');
+            assert.equal(decodedToken.sub, 'member@example.com');
+        });
+    });
+});