Updated Header-test description

prosjekt2/src/__tests__/Header.tests.js

@@ -2,7 +2,7 @@ import React from 'react';
 import Header from '../components/Header.jsx';
 import renderer from 'react-test-renderer'
 
-describe('Testing header.jsx',()=>{
+describe('Testing Header.jsx',()=>{
 
     //Creates an instance of the App component and checkes to see if it matches the snapshot.
     test('Snapshot match test', () => {