feat: add templates for python tests

templates/tests/py27.yml

+---
+py27:
+  before_script:
+    - pip install tox
+  stage: tests
+  script: tox -e py27
+  artifacts:
+    paths:
+      - py27-deprecated-warnings.json

templates/tests/py3.yml

+---
+py3:
+  before_script:
+    - pip install tox
+  stage: tests
+  script: tox -e py3
+  artifacts:
+    paths:
+      - py3-deprecated-warnings.json