Create a new release on every pull request merge (#1)

Using semantic versioning[1]

Use GoReleaser[2] to create a new release every time a pull request is
merged to master.
This requires each pull request to have a semantic version label, which
we enforce by using a label-checker GitHub Action[3].

[1] https://semver.org/
[2] https://goreleaser.com/ci/
[3] https://github.com/agilepathway/label-checker

NB we don't build an executable when releasing, as this is not
(currently, anyway) a Go project.

Author: johnboyes

.github/workflows/check_semver_labels.yml

@@ -0,0 +1,21 @@
+---
+name: Label Checker
+on:  # yamllint disable-line rule:truthy
+  pull_request:
+    types:
+      - opened
+      - synchronize
+      - reopened
+      - labeled
+      - unlabeled
+
+jobs:
+
+  check_semver_label:
+    name: Check for semantic version label
+    runs-on: ubuntu-latest
+    steps:
+      - uses: docker://agilepathway/pull-request-label-checker:latest
+        with:
+          one_of: major,minor,patch
+          repo_token: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/github_tag_and_release.yml

@@ -0,0 +1,46 @@
+name: Tag
+
+on:
+  pull_request:
+    types: 
+      - closed
+
+jobs:
+
+  tag:
+    name: Tag semantic version
+    runs-on: ubuntu-latest
+    steps:
+      - name: Tag 
+        uses: K-Phoen/[email protected]
+        with:
+          release_branch: master
+          release_strategy: tag
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+  release:
+    needs: tag
+    name: Create GitHub Release
+    runs-on: ubuntu-latest
+    steps:
+      -
+        name: Checkout
+        uses: actions/checkout@v2
+      -
+        name: Unshallow
+        run: git fetch --prune --unshallow
+      -
+        name: Set up Go
+        uses: actions/setup-go@v1
+        with:
+          go-version: 1.14.x
+      -
+        name: Run GoReleaser
+        uses: goreleaser/goreleaser-action@v1
+        with:
+          version: latest
+          args: release --rm-dist
+          key: ${{ secrets.YOUR_PRIVATE_KEY }}
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

.goreleaser.yml

@@ -0,0 +1,7 @@
+---
+project_name: label-checker
+build:
+  skip: true
+release:
+  github:
+  prerelease: auto