Fix the lint error

Author: gaearon

test/utils/identity.spec.js

@@ -4,7 +4,7 @@ import identity from '../../src/utils/identity';
 describe('Utils', () => {
   describe('identity', () => {
     it('should return first argument passed to it', () => {
-      var test = { 'a': 1 };
+      const test = { 'a': 1 };
       expect(identity(test, 'test')).toBe(test);
     });
   });