ci: run on multiple node and os versions (#156)

Author: timdeschryver

.github/workflows/ci.yml

@@ -4,11 +4,11 @@ on: pull_request
 
 jobs:
   build_and_test:
-    runs-on: ubuntu-latest
     strategy:
       matrix:
-        node-version: [12.x]
-
+        os: [ubuntu-latest, windows-latest]
+        node: [12, 14]
+    runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v1
       - name: use Node.js ${{ matrix.node-version }}