GitHub Actions: install Heroku CLI

https://github.com/AkhileshNS/heroku-deploy

Author: simon04

.github/workflows/build.yml

@@ -18,6 +18,9 @@ jobs:
         bundler-cache: true # runs 'bundle install' and caches installed gems automatically
     - name: Run tests
       run: bundle exec rake
+    - name: Install Heroku CLI
+      run: |
+        curl https://cli-assets.heroku.com/install.sh | sh
     - name: Deploy to Heroku
       uses: akhileshns/heroku-deploy@e3eb99d45a8e2ec5dca08735e089607befa4bf28 # v3.14.15
       with: