Resolve "Add competition login view"

Closes #21 (closed)

client/src/pages/admin/components/CompetitionManager.test.tsx

 import { render } from '@testing-library/react'
 import React from 'react'
+import { BrowserRouter } from 'react-router-dom'
 import CompetitionManager from './CompetitionManager'
 
 it('renders competition manager', () => {
-  render(<CompetitionManager />)
+  render(
+    <BrowserRouter>
+      <CompetitionManager />
+    </BrowserRouter>
+  )
 })