core -- Remove not working cache of py installed packages...

... and use env var for pip install location.

.gitlab-ci.yml

@@ -12,7 +12,7 @@ variables:
     REDIS_PASSWD: "dummy"
 
     # Cached packages
-    PYTHONPATH: "$CI_PROJECT_DIR/vendor/python"
+    PIP_CACHE_DIR: "$CI_PROJECT_DIR/vendor/pip"
 
     # postgres service configuration
     POSTGRES_PASSWORD: "4KZt3nGPLVeWSvtBZPSM3fSzXpzEU4"
@@ -24,18 +24,16 @@ variables:
 
 cache:
     paths:
-        - vendor/python
-        - vendor/pip
-        - vendor/apt
+        - vendor/
 
 before_script:
-    - mkdir -p vendor/{python,pip,apt}
+    - mkdir -p vendor/{pip,apt}
     - apt-get update -q && apt-get -o dir::cache::archives="vendor/apt" install -yqq postgresql-client
     - sed -E 's/^REDIS_HOST.*/REDIS_HOST = "redis"/' cof/settings/secret_example.py > cof/settings/secret.py
     - sed -i.bak -E 's;^REDIS_PASSWD = .*$;REDIS_PASSWD = "";' cof/settings/secret.py
     # Remove the old test database if it has not been done yet
     - psql --username=$POSTGRES_USER --host=$DBHOST -c "DROP DATABASE IF EXISTS test_$POSTGRES_DB"
-    - pip install --upgrade --cache-dir vendor/pip -t vendor/python -r requirements.txt
+    - pip install --upgrade -r requirements.txt
     - pip install coverage
     - python --version