django22: declare django2.2 in setup and tox (#51125)

setup.py

@@ -106,7 +106,7 @@ setup(
         'Programming Language :: Python :: 2',
     ],
     install_requires=[
-        'django>=1.11, <1.12',
+        'django>=1.11, <2.3',
     ],
     zip_safe=False,
     cmdclass={

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = py3-black-junit-coverage
+envlist = py3-django111-black-junit-coverage,py3-django22
 toxworkdir = {env:TMPDIR:/tmp}/tox-{env:USER}/passerelle-montpellier-encombrants/{env:BRANCH_NAME:}
 
 [testenv]
@@ -14,6 +14,8 @@ setenv =
   coverage: COVERAGE=--cov-report xml --cov-report html --cov=passerelle_montpellier_encombrants/
   junit: JUNIT=--junitxml=junit-{envname}.xml
 deps =
+  django111: django>=1.11, <1.12
+  django22: django>=2.2, <2.3
   https://git.entrouvert.org/passerelle.git/snapshot/passerelle-main.tar.gz
   psycopg2-binary
   xmlschema<1.1