function updateChangelog(version, releaseLog) {
  const changelog = fs.readFileSync('./CHANGELOG.md', 'utf8').split('\n')
  const fromLine = changelog.find(line => line.match(/##(\s|)\[unreleased\]?.+/i)) || changelog[0]

  return replace({
    files: 'CHANGELOG.md',
    from: fromLine,
    to: `${fromLine}\n\n${releaseVersionDate(version)}\n\n${releaseLog}`,
  })
    .then(changedFiles => {
      console.log('Modified files:', changedFiles.join(', '))
    })
    .catch(error => {
      console.error('Error occurred:', error)
    })
}
Updates README AND CHANGELOG
@param  {Object} version current and new version
@param  {String} releaseLog tickets in this release
@return {void}