Merge branch '33-use-separate-pip-cache-and-venv-for-every-python-version' into 'master'

Resolve "use separate pip cache and venv for every python version"

Closes #33

See merge request troebs/pycs!23

.gitlab-ci.yml

@@ -21,6 +21,7 @@ tests_3.6:
   variables:
     PIP_CACHE_DIR: "$CI_PROJECT_DIR/.cache/pip"
   cache:
+    key: "$CI_JOB_NAME"
     paths:
       - .cache/pip
       - env/
@@ -38,6 +39,7 @@ tests_3.7:
   variables:
     PIP_CACHE_DIR: "$CI_PROJECT_DIR/.cache/pip"
   cache:
+    key: "$CI_JOB_NAME"
     paths:
       - .cache/pip
       - env/
@@ -55,6 +57,7 @@ tests_3.8:
   variables:
     PIP_CACHE_DIR: "$CI_PROJECT_DIR/.cache/pip"
   cache:
+    key: "$CI_JOB_NAME"
     paths:
       - .cache/pip
       - env/
@@ -72,6 +75,7 @@ tests_3.9:
   variables:
     PIP_CACHE_DIR: "$CI_PROJECT_DIR/.cache/pip"
   cache:
+    key: "$CI_JOB_NAME"
     paths:
       - .cache/pip
       - env/