Add Django 3.1 to test matrix

Author: atodorov

.travis.yml

@@ -21,6 +21,12 @@ matrix:
       env: TOXENV=py37-dj30-sqlite
     - python: 3.8
       env: TOXENV=py38-dj30-sqlite
+    - python: 3.6
+      env: TOXENV=py36-dj31-sqlite
+    - python: 3.7
+      env: TOXENV=py37-dj31-sqlite
+    - python: 3.8
+      env: TOXENV=py38-dj31-sqlite
     - python: 3.6
       env: TOXENV=py36-djmaster-sqlite
     - python: 3.7
@@ -35,6 +41,10 @@ matrix:
       env: TOXENV=py38-dj30-postgresql
       addons:
         postgresql: "9.5"
+    - python: 3.8
+      env: TOXENV=py38-dj31-postgresql
+      addons:
+        postgresql: "9.5"
     - python: 3.8
       env: TOXENV=py38-dj22-mariadb
       addons:
@@ -50,6 +60,10 @@ matrix:
       env: TOXENV=py38-dj30-mariadb
       addons:
         mariadb: "10.3"
+    - python: 3.8
+      env: TOXENV=py38-dj31-mariadb
+      addons:
+        mariadb: "10.3"
       script:
         # working around https://travis-ci.community/t/mariadb-build-error-with-xenial/3160
         - mysql -u root -e "DROP USER IF EXISTS 'travis'@'%';"

tox.ini

@@ -5,14 +5,15 @@ envlist =
     style
     readme
     py{35,36,37,38}-dj22-sqlite
-    py{36,37,38}-dj30-sqlite
+    py{36,37,38}-dj{30,31}-sqlite
     py{36,37,38}-djmaster-sqlite
-    py{37,38}-dj{22,30}-{postgresql,mariadb}
+    py{37,38}-dj{22,30,31}-{postgresql,mariadb}
 
 [testenv]
 deps =
     dj22: Django==2.2.*
     dj30: Django==3.0.*
+    dj31: Django==3.1.*
     sqlite: mock
     postgresql: psycopg2-binary
     mariadb: mysqlclient