add a release workflow

.github/workflows/release.yml

@@ -0,0 +1,26 @@
+name: Push a new tag with minor update
+
+on:
+  push:
+    branches:
+      - master
+
+jobs:
+  release:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+
+      - uses: actions-ecosystem/action-get-latest-tag@v1
+        id: get-latest-tag
+
+      - uses: actions-ecosystem/action-bump-semver@v1
+        id: bump-semver
+        with:
+          current_version: ${{ steps.get-latest-tag.outputs.tag }}
+          level: minor
+
+      - uses: actions-ecosystem/action-push-tag@v1
+        with:
+          tag: ${{ steps.bump-semver.outputs.new_version }}
+          message: '${{ steps.bump-semver.outputs.new_version }}: PR #${{ github.event.pull_request.number }} ${{ github.event.pull_request.title }}'