GET requests on /view? return HTTP 301 with no Location header

[mlb-]

%:~ curl -iL "http://vim-doc.herokuapp.com/view?https://raw.github.com/kana/vim-tabpagecd/master/doc/tabpagecd.txt"
HTTP/1.1 301 Moved Permanently
Connection: keep-alive
X-Frame-Options: sameorigin
X-Xss-Protection: 1; mode=block
Content-Type: text/html;charset=utf-8
Content-Length: 0
Date: Tue, 04 Nov 2014 18:56:01 GMT
Server: thin 1.2.6 codename Crazy Delicious
Via: 1.1 vegur

%:~```