Authorization problem on parent server

If you have authorized in child registry with some credentials 
its passed to parent also and and making a problem to take package
information, something like 'invalid username or password' error returned 
even for public packages. 

so quick solution is to remove 'authorization' header when calling 
parent registry. 

 
_rewrite path update 

latest version of npmjs.org changed app package path 
from '/registry/_design/app/_rewrite/'
to '/registry/_design/scratch/_rewrite/'
Merge pull request #4 from sergey-byus/master

Authorization problem in parent registery fix