feat: add github actions for release (#117)

Author: Yiyiyimu

.github/workflows/release.yml

@@ -0,0 +1,45 @@
+name: Release
+
+on:
+  push:
+    tags:
+      - '*'
+
+jobs:
+  release:
+    name: Release
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+
+      - name: Install Lua
+        uses: leafo/gh-actions-lua@v8
+
+      - name: Install Luarocks
+        uses: leafo/gh-actions-luarocks@v4
+
+      - name: Extract tag name
+        id: tag_env
+        shell: bash
+        run: echo "##[set-output name=version;]$(echo ${GITHUB_REF##*/})"
+
+      # use ${tag:1} to filter out the heading "v" of "v1.0" 
+      - name: Upload to luarocks
+        env:
+          LUAROCKS_TOKEN: ${{ secrets.LUAROCKS_TOKEN }}
+        run: |
+          luarocks install dkjson
+          tag=${{ steps.tag_env.outputs.version }}
+          luarocks upload rockspec/lua-resty-etcd-${tag:1}-0.rockspec --api-key=${LUAROCKS_TOKEN}
+
+      - name: Create Release
+        id: create_release
+        uses: actions/create-release@v1
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          tag_name: ${{ steps.tag_env.outputs.version }}
+          release_name: ${{ steps.tag_env.outputs.version }}
+          draft: false
+          prerelease: false

MAINTAINING.md

@@ -0,0 +1,8 @@
+## Version Publish
+
+After [#117](https://github.com/api7/lua-resty-etcd/pull/117) got merged, we could publish new version of lua-resty-etcd easily. All you need to do is:
+
+- Create a PR that add the rockspec for the new version.
+- Create a tag with format like 'v1.0'.
+
+The tag would trigger Github Actions to upload to both luarocks and github release.