Simplify tox.ini

This uses the generative envlist and factor-conditional setting support
available since Tox 1.8:

http://tox.readthedocs.io/en/latest/config.html#generating-environments-conditional-settings

Author: PiDelport

tox.ini

@@ -1,86 +1,16 @@
 [tox]
-envlist = py27-dj1.8, py27-dj1.9, py27-dj1.10, py33-dj1.8, py34-dj1.8, py34-dj1.9, py34-dj1.10, py35-dj1.8, py35-dj1.9, py35-dj1.10, py36-dj1.8, py36-dj1.9, py36-dj1.10
+envlist =
+    py33-dj1.8,
+    py{27,34,35,36}-dj1.{8,9,10}
 
 [testenv]
 commands=python {toxinidir}/test_project/manage.py test test_app --noinput
 passenv = DJANGO_VERSION POSTGRES_USER POSTGRES_PASSWORD TRAVIS_BRANCH
           TRAVIS_COMMIT TRAVIS_LOG_LEVEL TRAVIS_PULL_REQUEST_BRANCH
           TRAVIS_REPO_SLUG
-
-[testenv:py27-dj1.8]
-basepython = python2.7
-deps =
-    django==1.8.14
-    psycopg2==2.6
-
-[testenv:py27-dj1.9]
-basepython = python2.7
-deps =
-    django==1.9.9
-    psycopg2==2.6
-
-[testenv:py27-dj1.10]
-basepython = python2.7
-deps =
-    django==1.10
-    psycopg2==2.6
-
-[testenv:py33-dj1.8]
-basepython = python3.3
-deps =
-    django==1.8.14
-    psycopg2==2.6
-
-[testenv:py34-dj1.8]
-basepython = python3.4
-deps =
-    django==1.8.14
-    psycopg2==2.6
-
-[testenv:py34-dj1.9]
-basepython = python3.4
-deps =
-    django==1.9.9
-    psycopg2==2.6
-
-[testenv:py34-dj1.10]
-basepython = python3.4
-deps =
-    django==1.10
-    psycopg2==2.6
-
-[testenv:py35-dj1.8]
-basepython = python3.5
-deps =
-    django==1.8.14
-    psycopg2==2.6
-
-[testenv:py35-dj1.9]
-basepython = python3.5
-deps =
-    django==1.9.9
-    psycopg2==2.6
-
-[testenv:py35-dj1.10]
-basepython = python3.5
 deps =
-    django==1.10
-    psycopg2==2.6
-
-[testenv:py36-dj1.8]
-basepython = python3.6
-deps =
-    django==1.8.14
-    psycopg2==2.6
+    dj1.8: Django ~=1.8.0
+    dj1.9: Django ~=1.9.0
+    dj1.10: Django ~=1.10.0
 
-[testenv:py36-dj1.9]
-basepython = python3.6
-deps =
-    django==1.9.9
-    psycopg2==2.6
-
-[testenv:py36-dj1.10]
-basepython = python3.6
-deps =
-    django==1.10
     psycopg2==2.6