code: function _normalizeUrl (route, prefix) {
    const _route = Object.assign({}, route)
    const url = _route.url
                   .replace(/^\//, '')
                   .replace(/\/$/, '')
  
    // build prefix
    prefix = prefix ? `/${prefix}` : ''
    _route.url = url ? `${prefix}/${url}/` : `${prefix}/`
  
    debug(`rewritting url: ${_route.url}`)
  
    return _route
  }
docs: clone and return route object after having normalized url
  @param  {Array.<Object>} route    imported route object
  @param  {String} prefix  route prefix to be added
  @return {Object}