support 1.7 and 1.6 request

[gpxlcj]

Hello,

I think it will be better to continue supporting the version under 1.8. And I try to add the origin code into the /django_markdown/urls.py

Thanks for your reading.

from django.conf.urls import url
from django import VERSION as version

from .views import preview

if (version[0] <=1) and (version[1] < 8):
    from django.conf.urls import patterns
    urlpatterns = patterns('', url('preview/$', preview, name='django_markdown_preview'))
else:
    urlpatterns = [
        url('preview/$', preview, name='django_markdown_preview')
    ]

[coveralls]

Coverage increased (+0.2%) to 64.224% when pulling 9c552c0 on master into ef4888d on develop.

[coveralls]

Coverage increased (+0.2%) to 64.224% when pulling 0bcf06b on master into ef4888d on develop.

[coveralls]

Coverage increased (+0.2%) to 64.224% when pulling 6d10ade on master into ef4888d on develop.

[sv0]

If you want to use django-markdown with Django<1.8 you can install
django-markdown==0.8.2 instead of latest one.