Add Python 3.4 to list of supported Python versions

Tests currently don't pass, but I'm hopeful they will in time for the
release of 0.8.

.travis.yml

 python:
   - '2.7'
   - '3.3'
+  - '3.4'
 
 env:
   global:
 matrix:
   allow_failures:
     - python: '3.3'
+    - python: '3.4'
 
 install:
   - easy_install Django==$DJANGO_VERSION

docs/source/releases/v0.8.rst

 Compatibility
 =============
 
+Oscar 0.8 is compatible with Django 1.5-1.7. Support for Python 2.6 has been
+dropped; it works with Python 2.7, Python 3.3 and Python 3.4.
+
 
 What's new in Oscar 0.8?
 ========================

tox.ini

 max-complexity = 10
 
 [tox]
-envlist = py27-1.5, py27-1.6, py33-1.5, py33-1.6
+envlist = py27-1.5, py27-1.6, py33-1.5, py33-1.6, py34-1.5, py34-1.6
 
 [testenv]
 commands = python runtests.py []
 deps = -r{toxinidir}/requirements.txt
        django==1.5.5
 
+[testenv:py34-1.5]
+basepython = python3.4
+deps = -r{toxinidir}/requirements.txt
+       django==1.5.5
+
 [testenv:py27-1.6]
 basepython = python2.7
 deps = -r{toxinidir}/requirements_py2.txt
 basepython = python3.3
 deps = -r{toxinidir}/requirements.txt
        django==1.6.1
+
+[testenv:py34-1.6]
+basepython = python3.4
+deps = -r{toxinidir}/requirements.txt
+       django==1.6.1