Create new release on PR merge

.github/workflows/release.yml

@@ -1,18 +1,28 @@
 name: "Release new version"
 
 on:
-  push:
+  pull_request:
     branches:
       - master
+    types:
+      - closed
 
 jobs:
   release:
     runs-on: ubuntu-latest
+    if: github.event.pull_request.merged == true && startsWith(github.event.pull_request.head.ref, 'release/')
     steps:
-      - uses: actions/checkout@v2
-      - name: Extract version from branch (what about hot fixes?)
-        run: |
-          echo "Hello world"
-      - name: Make new release on GitHub
+      - name: Extract version from branch name
         run: |
-          echo "Hello world"
+          BRANCH_NAME="${{ github.event.pull_request.head.ref }}"
+          VERSION=${BRANCH_NAME#release/}
+
+          echo "::set-env name=RELEASE_VERSION::$VERSION"
+      - uses: actions/checkout@v2
+      - name: Create Release
+        uses: actions/create-release@v1
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }} # This token is provided by Actions, you do not need to create your own token
+        with:
+          tag_name: ${{ env.RELEASE_VERSION }}
+          release_name: ${{ env.RELEASE_VERSION }}