Update testing.yml

Author: Austin-X

.github/workflows/testing.yml

@@ -7,7 +7,5 @@ jobs:
     - uses: actions/checkout@v2
     - name: Install modules
       run: yarn
-    - name: Change directory
-      run: cd course-matrix/frontend
     - name: Run tests
-      run: yarn test
+      run: cd course-matrix/frontend && yarn test