make docs build not update deps

.gitlab-ci.yml

@@ -52,7 +52,7 @@ docs:
   image: $PY35_IMAGE
   before_script:
     # install django deps
-    - pipenv install --dev
+    - pipenv --bare install --dev --ignore-pipfile
     # install doc deps
     - cd docs
     - pipenv run pip install -r requirements.txt

tox.ini

@@ -8,7 +8,7 @@ changedir={toxinidir}/website
 commands =
     ; Copy the env list to make not conflict with the Django version
     ; specified below
-    pipenv --bare install --dev
+    pipenv --bare install --dev --ignore-pipfile
     ; override using pip. Using pipenv would write to Pipfile!
     django20: pip install 'django>=2.0rc1,<2.1'
     django21: pip install --pre 'django>=2.1rc1,<2.2'