implement basic react testing suite

src/client/client.spec.js

@@ -0,0 +1,14 @@
+import '@testing-library/jest-dom/extend-expect';
+import React from 'react';
+import { render } from '@testing-library/react';
+import Separator from './components/elements/Paginator/Separator';
+
+describe('Components', () => {
+  describe('Paginator', () => {
+    it('separator - renders dash', () => {
+      const { getByText } = render(<Separator />);
+      const linkElement = getByText(/—/i); // &mdash;
+      expect(linkElement).toBeInTheDocument();
+    });
+  });
+});