Update pythonapp.yml

Author: timhughes

.github/workflows/pythonapp.yml

@@ -23,7 +23,7 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        python -m pip poetry
+        python -m pip install poetry
         poetry install
     - name: Lint with flake8
       run: |