Add ci workflow

.github/workflows/ci.yml

@@ -0,0 +1,95 @@
+name: CI
+on:
+  push:
+    branches: [master]
+  pull_request:
+    branches: [master]
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    outputs:
+      issue-number: ${{ steps.vars.outputs.issue-number }}
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-node@v1
+        with:
+          node-version: 12.x
+      - run: npm ci
+      - run: npm run test
+      - run: npm run package
+      - uses: actions/upload-artifact@v2
+        with:
+          name: dist
+          path: dist
+      - id: vars
+        run: |
+          if [[ "${{ github.event_name }}" == "pull_request" ]]; then \
+            echo "::set-output name=issue-number::${{ github.event.number }}" \
+          else \
+            echo "::set-output name=issue-number::1"; fi
+
+  test:
+    needs: [build]
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        target: [built, committed]
+    steps:
+      - uses: actions/checkout@v2
+      - if: matrix.target == 'built'
+        uses: actions/download-artifact@v2
+        with:
+          name: dist
+          path: dist
+
+      - name: Test create comment
+        uses: ./
+        id: couc
+        with:
+          issue-number: ${{ needs.build.outputs.issue-number }}
+          body: |
+            This is a multi-line test comment
+            - With GitHub **Markdown**
+            - Created by [create-or-update-comment][1]
+
+            [1]: https://github.com/peter-evans/create-or-update-comment
+          reactions: '+1'
+
+      - name: Test update comment
+        uses: ./
+        with:
+          comment-id: ${{ steps.couc.outputs.comment-id }}
+          body: |
+            **Edit:** Some additional info
+          reactions: eyes
+
+      - name: Test add reactions
+        uses: ./
+        with:
+          comment-id: ${{ steps.couc.outputs.comment-id }}
+          reactions: heart, hooray, laugh
+
+  package:
+    if: github.event_name == 'push' && github.ref == 'refs/heads/master'
+    needs: [test]
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/download-artifact@v2
+        with:
+          name: dist
+          path: dist
+      - name: Create Pull Request
+        uses: peter-evans/create-pull-request@v2
+        with:
+          commit-message: Update distribution
+          committer: GitHub <noreply@github.com>
+          author: ${{ github.actor }} <${{ github.actor }}@users.noreply.github.com>
+          title: Update distribution
+          body: |
+            - Updates the distribution for changes on `master`
+
+            Auto-generated by [create-pull-request][1]
+
+            [1]: https://github.com/peter-evans/create-pull-request
+          branch: update-distribution