def mirror( spec, upstream_host )
      raise Stickler::Repository::Error, "gem #{spec.full_name} already exists in remote repository" if remote_gem_file_exist?( spec )
      resource_request( mirror_resource( spec, upstream_host ) )
    end
def mirror( spec, upstream_host )
      raise Stickler::Repository::Error, "gem #{spec.full_name} already exists in remote repository" if remote_gem_file_exist?( spec )
      resource_request( mirror_resource( spec, upstream_host ) )
    end
Tell the remote repoistory to mirror the given gem from an upstream
 repository