Remove django 1.9 support and fix PEP8

tox.ini

@@ -1,6 +1,5 @@
 [tox]
 envlist =
-    py{27,34,35}-django19
     py{27,34,35}-django110
     py{27,34,35,36}-django111
     py{34,35,36}-django20
@@ -11,7 +10,6 @@ commands = py.test {posargs}
 extras = test
 pip_pre = true
 deps =
-    django19: django>=1.9,<1.10
     django110: django>=1.10,<1.11
     django111: django>=1.11,<2.0
     django20: django>=2.0