Remove Django < 1.11 support

Author: josephapg

.travis.yml

@@ -8,12 +8,6 @@ language: python
 matrix:
   fast_finish: true
   include:
-  - env: TOX_ENV=py27-django18
-    python: 2.7
-  - env: TOX_ENV=py27-django19
-    python: 2.7
-  - env: TOX_ENV=py27-django110
-    python: 2.7
   - env: TOX_ENV=py27-django111
     python: 2.7
   - env: TOX_ENV=py35-django20

examples/requirements/django_1_10.txt

@@ -1,6 +1,6 @@
 [tox]
 envlist =
-    py{27,35,36}-{django18,django19,django110,django111}
+    py{27,35,36}-{django111}
     py{35,36}-{django20}
     py{36,37}-{django111,django20,django21,django22}-{none,coreapischema}
 
@@ -11,9 +11,6 @@ envlogdir=
     examples/tmp/
 passenv = *
 deps =
-    django18: -r{toxinidir}/examples/requirements/django_1_8.txt
-    django19: -r{toxinidir}/examples/requirements/django_1_9.txt
-    django110: -r{toxinidir}/examples/requirements/django_1_10.txt
     django111: -r{toxinidir}/examples/requirements/django_1_11.txt
     django20: -r{toxinidir}/examples/requirements/django_2_0.txt
     django21: -r{toxinidir}/examples/requirements/django_2_1.txt