Added a view for downloading releasee packages

[taichino]

I've added a view to views/releases.py so that we can get uploaded packages from web and pip.

[thoas]

It's not a solution to download files via Django instead of pur web server such as Apache, Nginx.

You just need a rewrite rule in your web server such as (for nginx):

location ^~ /dists/ {
    alias /path/to/dists/;
}
rewrite  ^/simple/([\w\d_\.\-]+)/dists/(.*)$  /dists/$2  last;

And djangopypi needs serious documentation here.

[aquamatt]

Have added documentation about this in pull request #51 having found it to be lacking. A view is not required though as django static files can do the job for the dev server, and nginx/apache can do the job in production as noted by thoas. I have documented both cases.