(CI) change runner version

Author: qvalentin

.github/workflows/tests.yml

@@ -8,7 +8,7 @@ on:
       - 'package.json'
 jobs:
   runTests:
-    runs-on: ubuntu-16.04
+    runs-on: ubuntu-latest
     steps:
       - name: Checkout
         uses: actions/checkout@v2