code: def GET_user_profile( self, path_info, user_id ):
          
          if not check_name(user_id) and not check_subdomain(user_id):
              return self._reply_json({'error': 'Invalid name or subdomain'}, status_code=400)
  
          blockstackd_url = get_blockstackd_url()
          resp = blockstackd_client.resolve_profile(user_id, hostport=blockstackd_url)
          if json_is_error(resp):
              self._reply_json({'error': resp['error']}, status_code=404)
              return
  
          self._reply_json(resp['profile'])
          return
docs: Get a user profile.
          Reply the profile on success
          Return 404 on failure to load