Run CI for all Django versions for each Python one

.gitlab-ci.yml

@@ -17,18 +17,31 @@ before_script:
 python27:
   image: python:2.7
   stage: test
-  script: tox -e py27
+  script:
+    - tox -e django18-py27
+    - tox -e django19-py27
+    - tox -e django110-py27
+    - tox -e django111-py27
 
 python34:
   image: python:3.4
   stage: test
-  script: tox -e py34
+  script:
+    - tox -e django18-py34
+    - tox -e django19-py34
+    - tox -e django110-py34
+    - tox -e django111-py34
+    - tox -e django20-py34
 
 python35:
   image: python:3.5
   stage: test
   script:
-    - tox -e py35
+    - tox -e django18-py35
+    - tox -e django19-py35
+    - tox -e django110-py35
+    - tox -e django111-py35
+    - tox -e django20-py35
     - tox -e cov_combine
   # Catch coverage here. Python3.5 supports more Django versions.
   # For GitLab, keep this commented.
@@ -37,7 +50,9 @@ python35:
 python36:
   image: python:3.6
   stage: test
-  script: tox -e py36
+  script:
+    - tox -e django111-py36
+    - tox -e django20-py36
 
 flake8:
   image: python:3.6

tox.ini

@@ -1,4 +1,5 @@
 [tox]
+# Update .gitlab-ci.yml if you change the Django/Python matrix
 envlist =
     django{18,19,110}-py{27,34,35},
     django111-py{27,34,35,36},