Add job CI to do autobumps

.gitlab-ci.yml

 stages:
   - test
   - build
+  - release
 
 variables:
   PIP_CACHE_DIR: "$CI_PROJECT_DIR/.cache/pip"
@@ -42,3 +43,13 @@ tests:
 
   script:
     - tox
+
+bump-python-deps:
+  stage: release
+  image: registry.gitlab.com/teklia/devops:latest
+
+  only:
+    - schedules
+
+  script:
+    - devops python-deps requirements.txt