nm cache doesn't work with Poetry

Author: crccheck

.github/workflows/ci.yml

@@ -18,8 +18,8 @@ jobs:
       - uses: actions/setup-python@v2
         with:
           python-version: ${{ matrix.python }}
-          cache: "pip"
       - run: pip install poetry "Django<2.1"
+      - run: poetry install
       - run: make test
   test-dj21:
     strategy:
@@ -33,8 +33,8 @@ jobs:
       - uses: actions/setup-python@v2
         with:
           python-version: ${{ matrix.python }}
-          cache: "pip"
       - run: pip install poetry "Django<2.2"
+      - run: poetry install
       - run: make test
   test-dj22:
     strategy:
@@ -48,8 +48,8 @@ jobs:
       - uses: actions/setup-python@v2
         with:
           python-version: ${{ matrix.python }}
-          cache: "pip"
       - run: pip install poetry "Django<2.3"
+      - run: poetry install
       - run: make test
   test-dj30:
     strategy:
@@ -63,8 +63,8 @@ jobs:
       - uses: actions/setup-python@v2
         with:
           python-version: ${{ matrix.python }}
-          cache: "pip"
       - run: pip install poetry "Django<3.1"
+      - run: poetry install
       - run: make test
   test-dj31:
     strategy:
@@ -78,8 +78,8 @@ jobs:
       - uses: actions/setup-python@v2
         with:
           python-version: ${{ matrix.python }}
-          cache: "pip"
       - run: pip install poetry "Django<3.2"
+      - run: poetry install
       - run: make test
   test-dj32:
     strategy:
@@ -93,8 +93,8 @@ jobs:
       - uses: actions/setup-python@v2
         with:
           python-version: ${{ matrix.python }}
-          cache: "pip"
       - run: pip install poetry "Django<3.3"
+      - run: poetry install
       - run: make test
 
   lint: