Removing django 1.3 from tox and travis-ci matrices since it's no longer officially supported.

.travis.yml

@@ -1,6 +1,5 @@
 language: python
 env:
-  - DJANGO="django>=1.3,<1.4"
   - DJANGO="django>=1.4,<1.5"
   - DJANGO="django>=1.5,<1.6"
   - DJANGO="django>=1.6,<1.7"

requirements.txt

@@ -1,2 +1,2 @@
-Django>=1.3
+Django>=1.4
 shortuuid>=0.3

tox.ini

@@ -1,6 +1,6 @@
 [tox]
 downloadcache = {toxworkdir}/cache/
-envlist = py2.7-django.dev,py2.7-django1.5,py2.7-django1.4,py2.7-django1.3,py2.6-django.dev,py2.6-django1.5,py2.6-django1.4,py2.6-django1.3
+envlist = py2.7-django.dev,py2.7-django1.6,py2.7-django1.5,py2.7-django1.4,py2.6-django.dev,py2.6-django1.6,py2.6-django1.5,py2.6-django1.4
 
 [testenv]
 setenv =
@@ -29,11 +29,6 @@ basepython = python2.7
 deps = django>=1.4,<1.5
      {[testenv]deps}
 
-[testenv:py2.7-django1.3]
-basepython = python2.7
-deps = django>=1.3,<1.4
-     {[testenv]deps}
-
 [testenv:py2.6-django.dev]
 basepython = python2.6
 deps = https://github.com/django/django/zipball/master
@@ -53,9 +48,3 @@ deps = django>=1.5,<1.6
 basepython = python2.6
 deps = django>=1.4,<1.5
      {[testenv]deps}
-
-[testenv:py2.6-django1.3]
-basepython = python2.6
-deps = django>=1.3,<1.4
-     {[testenv]deps}
-