ci: run with multiple node versions

Signed-off-by: Kipras Melnikovas <kipras@kipras.org>

Author: kiprasmel

.github/workflows/test.yml

@@ -5,12 +5,15 @@ on: [push, workflow_dispatch]
 jobs:
   test:
     runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        node: [12, 14, 16]
 
     steps:
       - uses: actions/checkout@v2
       - uses: actions/setup-node@v2
         with:
-          node-version: "12"
+          node-version: ${{ matrix.node }}
       - run: yarn --frozen-lockfile
       - run: yarn test