def link_tag(protocol, fullpath, req_subdomain, view)
      view.tag :link, :rel => 'canonical', :href => url(protocol, fullpath, req_subdomain)
    end
def link_tag(protocol, fullpath, req_subdomain, view)
      view.tag :link, :rel => 'canonical', :href => url(protocol, fullpath, req_subdomain)
    end
Create a tag of this format:
  `<link rel="canonical" href="http://www.example.com/page-1" >`