Hotfix for Berkshelf to use latest mixlib-archive without chdir issue

BerksFix.ps1

# Filename: BerksFix.ps1
# Brian Dwyer - 8/22/18

$bad  = 'gem "mixlib-archive", "= 0.4.6"'
$good = 'gem "mixlib-archive", "= 0.4.13"'

$berks_cache = Resolve-Path '~\.berkshelf\cookbooks' -ErrorAction SilentlyContinue
if ($berks_cache) {
  'Clearing Berkshelf Cookbook Cache...'
  Remove-Item -Recurse $berks_cache
}

'Gathering installed mixlib-archive versions...'
$vers = $(chef exec gem list mixlib-archive)

If (($vers -match '0.4.13') -and ($vers -match '0.4.6')) {
  'Updated mixlib-archive already present... Nothing to do'
} Elseif ($vers -match '0.4.6') {
  'Detected faulty mixlib-archive version... Updating...'
  chef exec gem install mixlib-archive -v 0.4.13
  If ($lastexitcode -ne 0) { throw }
} Else {
  "Unknown versions detected... Script not designed for $vers"
  exit 1
}

$files = @('berks', 'kitchen')
foreach ($file in $files) {
  $filepath = [IO.Path]::Combine(($env:Path.Split(';') -match 'chefdk\\bin\\$')[0], $file)
  $content = Get-Content -Path $filepath
  if ( ($content -match $bad) ) {
    "Updating $file"
    $content -replace $bad, $good | Set-Content -Path $filepath
  } Else {
    "Content already up to date.  Nothing to do ($file)"
  }
}