Update ci.yml

added caching mechanism for requirements install

.github/workflows/ci.yml

@@ -12,7 +12,7 @@ jobs:
 
     strategy:
       matrix:
-        python-version: [3.9]
+        python-version: [3.8, 3.9, 3.10]
 
     steps:
     - name: Checkout code
@@ -23,6 +23,14 @@ jobs:
       with:
         python-version: ${{ matrix.python-version }}
 
+    - name: Cache pip
+      uses: actions/cache@v2
+      with:
+        path: ~/.cache/pip
+        key: ${{ runner.os }}-pip-${{ hashFiles('requirements.txt') }}
+        restore-keys: |
+          ${{ runner.os }}-pip-
+
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
@@ -37,3 +45,5 @@ jobs:
       run: |
         pip install pytest
         pytest
+
+        pytest