bump python and django versions in .travis.yml

Author: rustamzh

.travis.yml

@@ -1,15 +1,17 @@
 language: python
 
 python:
-  - "2.7"
-  - "3.2"
-  - "3.4"
+  - "3.5"
+  - "3.6"
+  - "3.7"
+  - "3.8"
 
 env:
-  - DJANGO=django==1.5.10
+  - DJANGO=django==2.2
+  - DJANGO=django==3.0
+  - DJANGO=django==3.1
 install:
   - pip install $DJANGO
-  - pip install -r requirements/travis-ci.txt
 
 script:
   - python runtests.py
@@ -18,18 +20,9 @@ branches:
     only:
         - master
 
-matrix:
-  include:
-    - python: "2.7"
-      env: DJANGO=django==1.6.6
-    - python: "2.7"
-      env: DJANGO=django==1.7
-    - python: "3.2"
-      env: DJANGO=django==1.7
-    - python: "3.4"
-      env: DJANGO=django==1.7
+jobs:
   exclude:
-    - python: "3.2"
-      env: DJANGO=django==1.5.10 --use-mirrors
-    - python: "3.4"
-      env: DJANGO=django==1.5.10 --use-mirrors
+    - python: "3.5"
+      env: DJANGO=django==3.0
+    - python: "3.5"
+      env: DJANGO=django==3.1

requirements/test.txt

@@ -1,2 +1 @@
 Django
-mock