update Tox and Travis to supported versions of Python and Django

Author: c17r

.travis.yml

@@ -4,22 +4,19 @@ python:
   - 3.4
   - 3.5
   - 3.6
+  - 3.7
 env:
-  - DJANGO=1.8
-  - DJANGO=1.9
-  - DJANGO=1.10
   - DJANGO=1.11
   - DJANGO=2.0
+  - DJANGO=2.1
 matrix:
   exclude:
     # Python/Django combinations that aren't officially supported
-    - { python: 3.6, env: DJANGO=1.8 }
-    - { python: 3.6, env: DJANGO=1.9 }
-    - { python: 3.6, env: DJANGO=1.10 }
     - { python: 2.7, env: DJANGO=2.0 }
+    - { python: 2.7, env: DJANGO=2.1 }
   include:
-    - { python: 3.6, env: TOXENV=flake8 }
-    - { python: 3.6, env: TOXENV=docs }
+    - { python: 3.7, env: TOXENV=flake8 }
+    - { python: 3.7, env: TOXENV=docs }
 
 install:
   - pip install tox-travis

tox.ini

@@ -6,18 +6,16 @@
 [tox]
 envlist =
     flake8
-    py{27,34,35}-django18
-    py{27,34,35}-django110
-    py{27,34,35,36}-django111
-    py{34,35,36}-django20
+    py{27,34,35,36,37}-django111
+    py{34,35,36,37}-django20
+    py{34,35,36,37}-django21
     docs
 
 [testenv]
 deps =
-    django18: Django>=1.8,<1.9
-    django110: Django>=1.10,<1.11
     django111: Django>=1.11,<2.0
     django20: Django>=2.0,<2.1
+    django21: Django>=2.1,<2.2
     py27: mock
 commands =
     python runtests.py
@@ -37,11 +35,9 @@ commands = flake8
 
 [travis:env]
 DJANGO =
-    1.8: django18
-    1.9: django19
-    1.10: django110
     1.11: django111
     2.0: django20
+    2.1: django21
 
 [flake8]
 exclude =