chore: add github release workflow (#35)

Co-authored-by: Pete Gautier <pete@momentohq.com>

.github/workflows/manual-release.yaml

@@ -0,0 +1,20 @@
+name: Manual Release
+# Triggers a merge from main->release, which will then trigger a release
+# from the release branch.
+on:
+  # Allows you to run this workflow manually from the Actions tab
+  workflow_dispatch:
+
+jobs:
+  merge-to-release-branch:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@main
+
+      - name: Merge main -> release
+        uses: devmasx/merge-branch@master
+        with:
+          type: now
+          from_branch: main
+          target_branch: release
+          github_token: ${{ secrets.MOMENTO_MACHINE_USER_GITHUB_TOKEN }}

.github/workflows/on-push-to-release.yaml

@@ -0,0 +1,67 @@
+name: On push to release
+
+on:
+  push:
+    branches: [ release ]
+
+jobs:
+  release:
+    runs-on: ubuntu-latest
+    outputs:
+      version: ${{ steps.release.outputs.release }}
+    steps:
+      - uses: actions/checkout@v3
+      - name: Set release
+        id: semrel
+        uses: go-semantic-release/action@v1
+        with:
+          github-token: ${{ secrets.MOMENTO_MACHINE_USER_GITHUB_TOKEN }}
+          allow-initial-development-versions: true
+          force-bump-patch-version: true
+          # For whatever reason, this silly tool won't let you do releases from branches
+          #  other than the default branch unless you pass this flag, which doesn't seem
+          #  to actually have anything to do with CI:
+          # https://github.com/go-semantic-release/semantic-release/blob/master/cmd/semantic-release/main.go#L173-L194
+          # https://github.com/go-semantic-release/condition-github/blob/4c8af3fc516151423fff2f77eb08bf7082570676/pkg/condition/github.go#L42-L44
+          custom-arguments: "--no-ci"
+
+      - name: Output release
+        id: release
+        run: echo "::set-output name=release::${{ steps.semrel.outputs.version }}"
+
+  test:
+    runs-on: ubuntu-latest
+    env:
+      TEST_AUTH_TOKEN: ${{ secrets.ALPHA_TEST_AUTH_TOKEN }}
+      TEST_CACHE_NAME: php-integration-test-cache
+
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Verify README generation
+        uses: momentohq/standards-and-practices/github-actions/oss-readme-template@gh-actions-v1
+        with:
+          project_status: official
+          project_stability: alpha
+          project_type: sdk
+          sdk_language: PHP
+          usage_example_path: ./examples/example.php
+
+      - name: Commitlint and Other Shared Build Steps
+        uses: momentohq/standards-and-practices/github-actions/shared-build@gh-actions-v1
+        env:
+          GITHUB_TOKEN: ${{ secrets.MOMENTO_MACHINE_USER_GITHUB_TOKEN }}
+
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: '8.1'
+          extensions: grpc
+          tools: composer
+
+      - name: Install dependencies
+        run: composer install
+
+      - name: Run tests
+        run: php vendor/phpunit/phpunit/phpunit --configuration phpunit.xml
+