build: use github action to build release

Author: alexkn

.github/workflows/release.yml

@@ -0,0 +1,24 @@
+name: Release
+
+on:
+  release:
+    types: [published]
+
+jobs:
+  publish-release:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: Install
+      run: yarn install
+    - name: Build
+      run: yarn run build
+    - name: Upload
+      uses: actions/upload-release-asset@v1.0.2
+      env:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      with:
+        upload_url: ${{ github.event.release.upload_url }}
+        asset_path: ./valetudo
+        asset_name: valetudo
+        asset_content_type: binary/octet-stream