Merge pull request #190 from macbre/pip-cache

CI: cache pip dependencies

Author: macbre

.github/workflows/tests.yml

@@ -44,6 +44,20 @@ jobs:
       with:
         python-version: ${{ matrix.python }}
 
+    # https://github.com/actions/cache/blob/main/examples.md#using-pip-to-get-cache-location
+    - name: Get pip cache dir
+      id: pip-cache
+      run: |
+        echo "::set-output name=dir::$(pip cache dir)"
+
+    - name: pip cache
+      uses: actions/cache@v2
+      with:
+        path: ${{ steps.pip-cache.outputs.dir }}
+        key: ${{ runner.os }}-pip-${{ hashFiles('**/requirements.txt', '**/setup.py') }}
+        restore-keys: |
+          ${{ runner.os }}-pip-
+
     - name: Install dependencies
       run: make install