A more generic way to create URL based template

    - As mentioned in issue 17, the method used assumes
      that the lookup field is 'pk', but this in fact can
      be anything. This fixes that issue.
      Another issue with the 'reverse¡ approac was that it wouldn't
      match ids which must include dashes or underscores, this
      takes care of that as well
Increasing coverage

    - Added test links when constructing for url templates
      when url are routed using namespaces
py3 support

    - urlparse was moved to urllib.parse in py3
Using six bundled in django to avoid extra deps
Merge pull request #19 from holandes22/master

A more generic way to create URL based template