Draft Github CI Pipeline (#17)

This commit defines a basic CI pipeline for releasing Pull-Pal to
prospective users. The artifacts include Pull-Pal's source and
container.

.github/workflows/build-tag-release.yml

@@ -0,0 +1,57 @@
+name: Build, Tag, and Release
+
+on:
+  workflow_dispatch
+  
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    
+    steps:
+      - name: Grep the Short SHA
+        uses: benjlevesque/short-sha@v2.2
+        id: short-sha
+        with:
+          length: 6
+          
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v3
+      
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Lint Dockerfile
+        uses: hadolint/hadolint-action@v3.1.0
+        with:
+          dockerfile: Dockerfile
+          failure-threshold: error
+  
+      - name: Build Docker Image
+        uses: docker/build-push-action@v2
+        with:
+          context: .
+          file: Dockerfile
+          tags: "pullpal:${{ steps.short-sha.outputs.sha }}"
+          push: false
+          load: true
+
+      - name: Smoke Test Container
+        run: docker run -d --name pullpal pullpal:${{ steps.short-sha.outputs.sha }}
+          
+      - name: Dump and Deflate Container
+        run: |
+          docker save pullpal:${{ steps.short-sha.outputs.sha }} \
+          | gzip -9kv > pullpalcontainer-${{ steps.short-sha.outputs.sha }}.tar.gz
+   
+      - name: Create Release 
+        id: create_release
+        uses: softprops/action-gh-release@v1
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          tag_name: "pullpal-${{ steps.short-sha.outputs.sha }}"
+          body: "A digital assistant that writes code and collaborates with humans on git repositories!"
+          files: pullpalcontainer-${{ steps.short-sha.outputs.sha }}.tar.gz