function readJSON(resp, info):Promise<object> {
  log.verbose('readJSON', resp, info)
  switch (info.rnfbEncode) {
    case 'base64':
      return Promise.resolve(resp.json())
    case 'path':
      return resp.json()
    default:
      return Promise.resolve(resp.json())
  }
}
Get response data as JSON object.
@param  {FetchBlobResponse} resp Response data object from RNFB fetch call.
@param  {RNFetchBlobResponseInfo} info Response informations.
@return {Promise<object>}