chore: restructure project into yarn workspaces, remove next

packages/design-system/atoms/button/Button.spec.tsx

@@ -0,0 +1,11 @@
+import { shallow } from 'enzyme';
+import * as React from 'react';
+import { Button } from './Button';
+
+it('fires an onClick callback when clicked', () => {
+    const mock = jest.fn();
+    const view = shallow(<Button onClick={mock}>Button</Button>);
+
+    view.simulate('click');
+    expect(mock).toBeCalled();
+});