chore(yamllint): add and integrate yamllint

.gitlab-ci.yml

@@ -21,3 +21,14 @@ py3:
   artifacts:
     paths:
       - py3-deprecated-warnings.json
+
+yamllint:
+  stage: lint
+  rules:
+    - changes:
+        - "**/*.yaml"
+        - "*.yaml"
+        - "**/*.yml"
+        - "*.yml"
+  script:
+    - tox -e yamllint

.yamllint

+extends: default
+
+rules:
+  document-start: disable
+  line-length: disable
+  indentation:
+    spaces: 2

MANIFEST.in

@@ -11,3 +11,4 @@ include tox.ini
 prune debian
 exclude cubicweb-blog.spec
 exclude .gitlab-ci.yml
+exclude .yamllint

tox.ini

 [tox]
-envlist = py3, flake8, check-manifest
+envlist = py3, flake8, check-manifest, yamllint
 
 [testenv]
 deps =
@@ -72,3 +72,8 @@ commands =
   sh -c "cd dist && dcmd zip latest.zip *.changes"
   http -f POST https://{env:JENKINS_USER}:{env:JENKINS_TOKEN}@jenkins.intra.logilab.fr/job/pkg-from-dsc/buildWithParameters DIST=buster source.zip@dist/latest.zip REPO=buster PUBLISH=true
 
+[testenv:yamllint]
+skip_install = true
+deps = yamllint
+commands =
+  yamllint .