Update Sitecore NuGet packages

Update-SitecorePackages.ps1

# Updates from a specific version to avoid conflicting names ("Sitecore.Framework", "Sitecore.Ship", etc)
$SourceVersion = "9.0.171002"

# Does late filtering to avoid redundant upgrades for packages that have already been upgrades as dependencies. Big time saver
Get-Package | `
  Where-Object { $_.Id -like "Sitecore.*" } | `
  Foreach-Object {
    $id = $_.Id
    if ((Get-Package -ProjectName $_.ProjectName) | ?{ $_.Id -eq $id -and $_.Version -eq $SourceVersion}) {
      Update-Package -Id $_.Id -ProjectName $_.ProjectName -Version HighestPatch # Use HighestMinor for a full point release
    }
  }