add s3 sync action

.github/workflows/s3-sync.yml

@@ -0,0 +1,16 @@
+name: Sync to S3
+
+on: [push, pull_request]
+
+jobs:
+  sync:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@master
+      - uses: jakejarvis/s3-sync-action@master
+        env:
+          AWS_S3_BUCKET: ${{ vars.ENGRID_S3_BUCKET_NAME }}
+          AWS_ACCESS_KEY_ID: ${{ secrets.ENGRID_S3_ACCESS_KEY }}
+          AWS_SECRET_ACCESS_KEY: ${{ secrets.ENGRID_S3_SECRET_KEY }}
+          SOURCE_DIR: 'dist'
+          DEST_DIR: '${{ github.event.repository.name }}/${{ github.head_ref || github.ref_name }}'