Fix re-export of component and add test

Author: danez

src/__tests__/index.spec.js

@@ -0,0 +1,11 @@
+/* global describe, it */
+import React from 'react';
+import { shallow } from 'enzyme';
+import Highlight from '../index';
+import { expect } from 'chai';
+
+describe('index.js', () => {
+  it('exports default component', () => {
+    expect(() => shallow(<Highlight>test</Highlight>)).to.not.throw(Error);
+  });
+});

src/index.js

@@ -1,2 +1,2 @@
 /* @flow */
-export { default as Highlight } from './components/Highlight';
+export { default } from './components/Highlight';