simplify build by moving away from setting up and configuring poetry on every job run

Author: purificant

.github/workflows/ci.yaml

@@ -10,11 +10,6 @@ jobs:
       matrix:
         python-version: ['3.6', '3.7', '3.8', '3.9']
         os: ['ubuntu-20.04', 'macos-10.15', 'windows-2019']
-        include:
-          - os: ['ubuntu-20.04', 'macos-10.15']
-            poetry-path: ['$HOME/.poetry/bin']
-          - os: ['windows-2019']
-            poetry-path: ['%USERPROFILE%\.poetry\bin']
       fail-fast: false
     name: Python ${{ matrix.python-version }} on ${{ matrix.os }}
     runs-on: ${{ matrix.os }}
@@ -25,17 +20,15 @@ jobs:
         uses: actions/setup-python@v2
         with:
           python-version: ${{ matrix.python-version }}
-      - name: Install poetry
-        run: make get-poetry
-      - name: Enable poetry command
-        run: echo "${{ matrix.poetry-path }}" >> $GITHUB_PATH
-      - name: Configure poetry
-        run: poetry config virtualenvs.create false # disable creating virtual environment
       - name: Install dependencies
-        run: make install
+        run: pip install -r requirements-dev.txt
+        shell: bash
       - name: Check code formatting
         run: black --check .
+        shell: bash
       - name: Lint code
         run: make lint
+        shell: bash
       - name: Run tests with code coverage
         run: make coverage
+        shell: bash