CHEF-1940:Patch for https://github.com/opscode/chef/issues/1940

Attached patch for - https://github.com/opscode/chef/issues/1940
Travis reports this is failing in Chef::HTTP where we parse the url (as a string) using URI.parse. Here you're turning the string into a URI object.

If you wanted to rely on URI to parse the string here you probably could, just don't set the result to url.

```
 Failure/Error: knife('upload --purge /cookbooks/x').should_succeed <<EOM
     NoMethodError:
       undefined method `gsub' for #<URI::HTTP:0x0000001a729ce0 URL:http://127.0.0.1:8900>
```