Fixes missing identity value in token when it's not a string (#484)

.gitignore

@@ -22,3 +22,6 @@ config.js
 
 ### jsdoc dir ###
 docs
+
+### ide / editors ###
+.vscode

lib/jwt/AccessToken.js

@@ -249,7 +249,7 @@ _.extend(AccessToken.prototype, {
     }
 
     var grants = {};
-    if (_.isString(this.identity)) { grants.identity = this.identity; }
+    if (_.isInteger(this.identity) || _.isString(this.identity)) { grants.identity = String(this.identity); }
 
     _.each(this.grants, function(grant) {
       grants[grant.key] = grant.toPayload();

spec/unit/jwt/AccessToken.spec.js

@@ -28,6 +28,11 @@ describe('AccessToken', function() {
     it('should require secret', function() {
       expect(initWithoutIndex(2)).toThrow(new Error('secret is required'));
     });
+    it('should convert identity from integer to string', function () {
+      var token = new twilio.jwt.AccessToken(accountSid, keySid, 'secret', { identity: 4444 });
+      var decoded = jwt.decode(token.toJwt());
+      expect(decoded.grants.identity).toEqual('4444');
+    });
   });
 
   describe('generate', function() {