Fix test_cache_url_value for newer django-cache-url
Fix test_cache_url_value for newer django-cache-url

This fixes the following failure:

    ERROR: test_cache_url_value (tests.test_values.ValueTests)
    ----------------------------------------------------------------------
    Traceback (most recent call last):
      File "…/django-configurations/configurations/values.py", line 158, in to_python
        return self._caster(value)
      File "…/django-configurations/.tox/py34-dj18/lib/python3.4/site-packages/django_cache_url.py", line 98, in parse
        config['LOCATION'] = "%s:%s:%s" % (url.hostname, url.port, db)
      File "…/pyenv/3.4.3/lib/python3.4/urllib/parse.py", line 156, in port
        port = int(port, 10)
    ValueError: invalid literal for int() with base 10: 'port'

    During handling of the above exception, another exception occurred:

    Traceback (most recent call last):
      File "…/django-configurations/tests/test_values.py", line 415, in test_cache_url_value
        value = CacheURLValue(cache_url)
      File "…/django-configurations/configurations/values.py", line 420, in __init__
        self.default = self.to_python(self.default)
      File "…/django-configurations/configurations/values.py", line 423, in to_python
        value = super(DictBackendMixin, self).to_python(value)
      File "…/django-configurations/configurations/values.py", line 160, in to_python
        raise ValueError(self.message.format(value))
    ValueError: Cannot interpret cache URL value 'redis://user@host:port/1'

    ----------------------------------------------------------------------
    Ran 63 tests in 1.132s

    FAILED (errors=1)

jezdez/django-configurations,jazzband/django-configurations,jazzband/django-configurations,gatherhealth/django-configurations