Add cache for CI

.github/workflows/testing.yaml

@@ -20,10 +20,20 @@ jobs:
       run: |
         curl -sSL https://raw.githubusercontent.com/python-poetry/poetry/master/install-poetry.py | python -
         echo "${HOME}/.local/bin" >> $GITHUB_PATH
-    - name: Install Dependencies
+    - name: Configure poetry
       run: |
-        pip install -U pip
-        poetry install
+        poetry config virtualenvs.create true
+        poetry config virtualenvs.in-project true
+    - name: Cache poetry venv
+      uses: actions/cache@v2
+      id: poetry-cache
+      with:
+        path: .venv
+        key: venv-${{ runner.os }}-poetry-${{ hashFiles('**/poetry.lock') }}
+        restore-keys: venv-${{ runner.os }}-poetry-
+    - name: Install Dependencies
+      if: steps.poetry-cache.outputs.cache-hit != 'true'
+      run: poetry install
     - name: Isort check
       run: |
         poetry run isort meilisearch_status_check_decorator tests --check-only
@@ -39,7 +49,6 @@ jobs:
     - name: mypy check
       run: |
         poetry run mypy meilisearch_status_check_decorator
-
   testing:
     strategy:
       fail-fast: false
@@ -56,14 +65,24 @@ jobs:
       run: |
         curl -sSL https://raw.githubusercontent.com/python-poetry/poetry/master/install-poetry.py | python -
         echo "${HOME}/.local/bin" >> $GITHUB_PATH
-    - name: Poetry configuration
-      if: matrix.python-version == '3.10.0-beta - 3.10.0'  # Poetry installs are currently failing with experimental installer on 3.10
+    - name: Configure poetry
+      run: |
+        poetry config virtualenvs.create true
+        poetry config virtualenvs.in-project true
+    - name: Configure poetry Python 3.10
+      if: matrix.python-version == '3.10.0-beta - 3.10.0'  # Poetry installs are currently failing with the experimental installer on 3.10
       run: |
         poetry config experimental.new-installer false
+    - name: Cache poetry venv
+      uses: actions/cache@v2
+      id: poetry-cache
+      with:
+        path: .venv
+        key: venv-${{ runner.os }}-poetry-${{ hashFiles('**/poetry.lock') }}
+        restore-keys: venv-${{ runner.os }}-poetry-
     - name: Install Dependencies
-      run: |
-        pip install -U pip
-        poetry install
+      if: steps.poetry-cache.outputs.cache-hit != 'true'
+      run: poetry install
     - name: MeiliSearch (latest version) setup with Docker
       run: |
         docker run -d -p 7700:7700 getmeili/meilisearch:latest ./meilisearch --no-analytics=true --master-key=masterKey