Add release automation

.github/workflows/create-release.yml

@@ -0,0 +1,41 @@
+name: "Create release"
+
+on:
+  pull_request:
+    types:
+      - closed
+
+jobs:
+  create_release:
+    name: Create from merged release branch
+    if: github.event.pull_request.merged == true && startsWith(github.event.pull_request.head.ref, 'release/')
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2.3.4
+
+      - name: Extract version from branch name
+        id: extract-version
+        shell: python
+        run: |
+          branch_name = "${{ github.event.pull_request.head.ref }}"
+          version = branch_name.split("/")[1]
+
+          print(f"::set-output name=version::{version}")
+
+      - name: Extract changelog section for release
+        id: changelog
+        uses: coditory/changelog-parser@v1
+        with:
+          version: ${{ steps.extract-version.outputs.version }}
+
+      - name: Create GitHub release
+        uses: actions/create-release@v1
+        env:
+          GITHUB_TOKEN: ${{ secrets.PERSONAL_ACCESS_TOKEN }}
+        with:
+          tag_name: ${{ steps.extract-version.outputs.version }}
+          release_name: ${{ steps.extract-version.outputs.version }}
+          draft: false
+          prerelease: false
+          body: ${{ steps.changelog.outputs.description }}
+          commitish: ${{ github.event.pull_request.merge_commit_sha }}

.github/workflows/draft-new-release.yml

@@ -0,0 +1,65 @@
+name: "Draft new release"
+
+on:
+  workflow_dispatch:
+    inputs:
+      version:
+        description: 'The new version in X.Y.Z format.'
+        required: true
+
+jobs:
+  draft-new-release:
+    name: "Draft a new release"
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2.3.4
+
+      - name: Create release branch
+        run: git checkout -b release/${{ github.event.inputs.version }}
+
+      - name: Update changelog
+        uses: thomaseizinger/keep-a-changelog-new-release@1.2.1
+        with:
+          version: ${{ github.event.inputs.version }}
+          changelogPath: CHANGELOG.md
+
+      - name: Initialize mandatory git config
+        run: |
+          git config user.name "Thomas Eizinger"
+          git config user.email thomas@eizinger.io
+
+      - name: Bump version in Cargo.toml
+        uses: thomaseizinger/set-crate-version@1.0.0
+        with:
+          version: ${{ github.event.inputs.version }}
+          manifest: Cargo.toml
+
+      - name: Commit changelog and manifest files
+        id: make-commit
+        run: |
+          curl -fsSL https://dprint.dev/install.sh | sh
+          /home/runner/.dprint/bin/dprint fmt
+
+          git add CHANGELOG.md Cargo.toml
+          git commit --message "Prepare release ${{ github.event.inputs.version }}"
+
+          echo "::set-output name=commit::$(git rev-parse HEAD)"
+
+      - name: Push new branch
+        run: git push origin release/${{ github.event.inputs.version }} --force
+
+      - name: Create pull request
+        uses: thomaseizinger/create-pull-request@1.1.0
+        with:
+          GITHUB_TOKEN: ${{ secrets.PERSONAL_ACCESS_TOKEN }}
+          head: release/${{ github.event.inputs.version }}
+          base: master
+          title: Release version ${{ github.event.inputs.version }}
+          reviewers: ${{ github.actor }}
+          body: |
+            Hi @${{ github.actor }}!
+
+            This PR was created in response to a manual trigger of the release workflow here: https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}.
+            I've updated the changelog and bumped the versions in the manifest files in this commit: ${{ steps.make-commit.outputs.commit }}.
+
+            Merging this PR will create a GitHub release and publish the library to crates.io!

.github/workflows/release-to-crates-io.yml

@@ -0,0 +1,18 @@
+name: "Release to crates.io"
+
+on:
+  release:
+    types: [created]
+
+jobs:
+  release:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout tagged commit
+        uses: actions/checkout@v2.3.4
+        with:
+          ref: ${{ github.event.release.target_commitish }}
+
+      - run: cargo publish --dry-run
+        env:
+          CARGO_REGISTRY_TOKEN: ${{ secrets.CARGO_REGISTRY_TOKEN }}