build: make it fail in case of pylint warnings (#62099)

pylint.sh

@@ -2,4 +2,4 @@
 set -e -x
 env
 
-pylint -f parseable --rcfile pylint.rc "$@" | tee pylint.out || /bin/true
+pylint -f parseable --rcfile pylint.rc "$@" | tee pylint.out; test $PIPESTATUS -eq 0

tox.ini

@@ -1,6 +1,6 @@
 [tox]
 toxworkdir = {env:TMPDIR:/tmp}/tox-{env:USER}/passerelle/{env:BRANCH_NAME:}
-envlist = py3-django22-xmlschema14-codestyle-coverage,py3-django22-xmlschema10
+envlist = py3-django22-xmlschema14-codestyle-coverage,py3-django22-xmlschema10,pylint
 
 [testenv]
 usedevelop = True
@@ -24,8 +24,6 @@ deps =
   mock<4
   httmock
   python-dateutil
-  pylint
-  pylint-django
   django-webtest<1.9.3
   lxml
   mohawk
@@ -45,7 +43,6 @@ deps =
 commands =
   ./get_wcs.sh
   py.test {posargs: {env:FAST:} {env:COVERAGE:} {env:JUNIT:} tests/}
-  coverage: ./pylint.sh passerelle/
   codestyle: pre-commit run --all-files --show-diff-on-failure
 
 [pytest]
@@ -57,3 +54,24 @@ filterwarnings = default
    module:.*init.*authority.*code.*syntax is deprecated:DeprecationWarning:pyproj
 # wcs root directory must be renamed to fix this one
    ignore:Not importing directory.*/wcs':ImportWarning
+
+[testenv:pylint]
+setenv =
+  DJANGO_SETTINGS_MODULE=passerelle.settings
+  PASSERELLE_SETTINGS_FILE=tests/settings.py
+  BRANCH_NAME={env:BRANCH_NAME:}
+  SETUPTOOLS_USE_DISTUTILS=stdlib
+deps =
+  pytest-django
+  pytest!=6.0.0
+  WebTest
+  mock<4
+  httmock
+  pylint
+  pylint-django
+  django-webtest<1.9.3
+  pytest-freezegun
+  responses
+  mohawk
+commands =
+  ./pylint.sh passerelle/ tests/