Update build-and-test.yml

Added installation of python3-beancount in dependencies.

.github/workflows/build-and-test.yml

@@ -29,6 +29,7 @@ jobs:
         pip install flake8 pytest
         if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
         sudo -H python -m pip install beancount
+        sudo apt-get install python3-beancount
     - name: Lint with flake8
       run: |
         # stop the build if there are Python syntax errors or undefined names