Create releases for tags

Signed-off-by: Scott Andrews <andrewssc@vmware.com>

Author: scothis

.github/workflows/ci.yaml

@@ -29,3 +29,36 @@ jobs:
       with:
         name: knative.js
         path: ./dist/knative.js
+
+  release:
+    needs: build
+    if: startsWith(github.ref, 'refs/tags/')
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2.3.3
+    - name: Get release version
+      id: get-version
+      run: |
+        echo ::set-output name=version::$(cat package.json | jq -r .version)
+    - name: Draft release
+      id: create_release
+      uses: actions/create-release@v1.1.4
+      env:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      with:
+        tag_name: ${{ github.ref }}
+        release_name: Release ${{ github.ref }}
+        draft: true
+    - name: Download staged build
+      uses: actions/download-artifact@v2.0.5
+      with:
+        name: knative.js
+    - name: Upload release
+      uses: actions/upload-release-asset@v1.0.2
+      env:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      with:
+        upload_url: ${{ steps.create_release.outputs.upload_url }} # This pulls from the CREATE RELEASE step above, referencing it's ID to get its outputs object, which include a `upload_url`. See this blog post for more info: https://jasonet.co/posts/new-features-of-github-actions/#passing-data-to-future-steps
+        asset_path: knative.js
+        asset_name: knative-${{ steps.get-version.outputs.version }}.js
+        asset_content_type: text/javascript