diff --git a/.gitignore b/.gitignore
index e817f4d..8351c11 100644
--- a/.gitignore
+++ b/.gitignore
@@ -10,4 +10,7 @@ __pycache__
 
 # Vim
 *.swp
-*.swo
\ No newline at end of file
+*.swo
+
+# Tests
+.tox
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
new file mode 100644
index 0000000..073fdbd
--- /dev/null
+++ b/.gitlab-ci.yml
@@ -0,0 +1,54 @@
+image: python
+
+stages:
+  - linters
+  - tests
+
+variables:
+  PIP_CACHE_DIR: "$CI_PROJECT_DIR/vendor/pip"
+
+cache:
+  paths:
+    - vendor
+
+linters:
+  stage: linters
+  before_script:
+    - mkdir -p vendor/pip
+    - pip install --upgrade black isort flake8
+  script:
+    - black --check .
+    - isort --check --diff .
+    - flake8 --exit-zero authens
+
+before_script:
+  - mkdir -p vendor/{apt,pip}
+  - apt-get update -q && apt-get -o dir::cache::archives="vendor/apt" install -yqq python3-dev libldap2-dev libsasl2-dev
+  - pip install tox
+
+python35:
+  image: python:3.5
+  stage: tests
+  script:
+    - tox -e py35-django22
+
+python36:
+  image: python:3.6
+  stage: tests
+  script:
+    - tox -e py36-django22
+    - tox -e py36-django30
+
+python37:
+  image: python:3.7
+  stage: tests
+  script:
+    - tox -e py37-django22
+    - tox -e py37-django30
+
+python38:
+  image: python:3.8
+  stage: tests
+  script:
+    - tox -e py38-django22
+    - tox -e py38-django30
diff --git a/authens/forms.py b/authens/forms.py
index e1def13..55ab14c 100644
--- a/authens/forms.py
+++ b/authens/forms.py
@@ -1,7 +1,7 @@
 from django import forms
-from django.contrib.auth import forms as auth_forms, authenticate
-from django.utils.translation import gettext_lazy as _
+from django.contrib.auth import authenticate, forms as auth_forms
 from django.utils import timezone
+from django.utils.translation import gettext_lazy as _
 
 
 def promo_choices():
diff --git a/authens/migrations/0001_initial.py b/authens/migrations/0001_initial.py
index 60b14d3..e48b86f 100644
--- a/authens/migrations/0001_initial.py
+++ b/authens/migrations/0001_initial.py
@@ -1,8 +1,7 @@
 # Generated by Django 3.0.6 on 2020-05-17 11:58
-
+import django.db.models.deletion
 from django.conf import settings
 from django.db import migrations, models
-import django.db.models.deletion
 
 
 class Migration(migrations.Migration):
diff --git a/authens/migrations/0002_old_cas_account.py b/authens/migrations/0002_old_cas_account.py
index defdac9..d7a0a89 100644
--- a/authens/migrations/0002_old_cas_account.py
+++ b/authens/migrations/0002_old_cas_account.py
@@ -1,8 +1,7 @@
 # Generated by Django 3.0.6 on 2020-06-12 17:26
-
+import django.db.models.deletion
 from django.conf import settings
 from django.db import migrations, models
-import django.db.models.deletion
 
 
 class Migration(migrations.Migration):
diff --git a/authens/shortcuts.py b/authens/shortcuts.py
index 8a8dd97..2bed72b 100644
--- a/authens/shortcuts.py
+++ b/authens/shortcuts.py
@@ -2,7 +2,6 @@
 
 # TODO: make the python-ldap dependency optional
 import ldap
-
 from django.conf import settings
 from django.contrib.auth import get_user_model
 
diff --git a/authens/utils.py b/authens/utils.py
index a7cbbb6..2dc0876 100644
--- a/authens/utils.py
+++ b/authens/utils.py
@@ -1,7 +1,7 @@
 """Internal utility functions used by authens."""
+from urllib.parse import urlunparse
 
 from cas import CASClient
-from urllib.parse import urlunparse
 
 
 def get_cas_client(request):
diff --git a/authens/views.py b/authens/views.py
index c1d4f66..70134ad 100644
--- a/authens/views.py
+++ b/authens/views.py
@@ -6,9 +6,9 @@ from django.contrib.auth import views as auth_views
 from django.contrib.messages.views import SuccessMessageMixin
 from django.core.exceptions import PermissionDenied
 from django.shortcuts import redirect
+from django.urls import reverse_lazy
 from django.utils import timezone
 from django.utils.translation import gettext_lazy as _
-from django.urls import reverse_lazy
 from django.views.generic import TemplateView, View
 
 from authens.forms import OldCASAuthForm
diff --git a/example_site/example_site/urls.py b/example_site/example_site/urls.py
index 0781d66..ebb6718 100644
--- a/example_site/example_site/urls.py
+++ b/example_site/example_site/urls.py
@@ -15,7 +15,6 @@ Including another URLconf
 """
 from django.contrib import admin
 from django.urls import include, path
-
 from example import views
 
 urlpatterns = [
diff --git a/requirements.txt b/requirements.txt
index 6421f80..d281cf0 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1 +1,2 @@
 python-cas==1.5.*
+python-ldap
diff --git a/runtests.py b/runtests.py
index f9079d6..0bc3f88 100644
--- a/runtests.py
+++ b/runtests.py
@@ -8,8 +8,8 @@ import django
 from django.conf import settings
 from django.test.utils import get_runner
 
-if __name__ == '__main__':
-    os.environ['DJANGO_SETTINGS_MODULE'] = 'tests.settings'
+if __name__ == "__main__":
+    os.environ["DJANGO_SETTINGS_MODULE"] = "tests.settings"
     django.setup()
     TestRunner = get_runner(settings)
     test_runner = TestRunner()
diff --git a/setup.cfg b/setup.cfg
index ec50b39..cd19421 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -19,5 +19,4 @@ known_django = django
 known_first_party = authens,tests
 line_length = 88
 multi_line_output = 3
-not_skip = __init__.py
 sections = FUTURE,STDLIB,THIRDPARTY,FIRSTPARTY,LOCALFOLDER
diff --git a/tests/urls.py b/tests/urls.py
index ab97673..53bcab9 100644
--- a/tests/urls.py
+++ b/tests/urls.py
@@ -2,11 +2,11 @@ from django.contrib.auth.decorators import login_required
 from django.http import HttpResponse
 from django.urls import include, path
 
-
 # ---
 # Two tiny views to easily test user authentication.
 # ---
 
+
 def public_view(request):
     return HttpResponse("OK")
 
diff --git a/tox.ini b/tox.ini
new file mode 100644
index 0000000..86d1123
--- /dev/null
+++ b/tox.ini
@@ -0,0 +1,16 @@
+[tox]
+# Temporaire en attendant de créer setup.py
+skipsdist = True
+envlist =
+  py{35,36,37,38}-django22,
+  py{36,37,38}-django30
+
+[testenv]
+deps =
+  django22: Django==2.2.*
+  django30: Django==3.0.*
+  python-cas
+  python-ldap
+commands =
+  python --version
+  python runtests.py