Use node 14 in CI

Author: nicolasstucki

.github/workflows/continuous-integration.yml

@@ -13,13 +13,15 @@ jobs:
   build-and-test:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
-      - uses: actions/setup-node@v1
+      - uses: actions/checkout@v3
+      - uses: actions/setup-node@v3
+        with:
+          node-version: '14'
       - name: Cache Node.js modules
         uses: actions/cache@v2
         with:
           path: "**/node_modules"
           key: ${{ runner.os }}-modules-${{ hashFiles('**/yarn.lock') }}
-      - run: yarn 
+      - run: yarn
       - run: yarn build
       - run: yarn test