Add github pdk workflow

.github/workflows/pdk.yml

@@ -0,0 +1,20 @@
+name: pdk
+on:
+  - push
+  - pull_request
+jobs:
+  tests:
+    runs-on: ubuntu-latest
+    steps:
+      - name: checkout
+        uses: actions/checkout@v2
+
+      - name: validate
+        uses: okopop/pdk@main
+        with:
+          action: 'validate'
+
+      - name: unit test
+        uses: okopop/pdk@main
+        with:
+          action: 'test unit'