Add prime Numbers and install poetry

.github/workflows/github-actions-demo.yml

@@ -6,6 +6,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - run: python --version
+      - run: poetry --version
       - run: echo "🎉 The job was automatically triggered by a ${{ github.event_name }} event."
       - run: echo "🐧 This job is now running on a ${{ runner.os }} server hosted by GitHub!"
       - run: echo "🔎 The name of your branch is ${{ github.ref }} and your repository is ${{ github.repository }}."