Updated stale link to ex-MS employee's repo

The repo referenced in this file for getting the docker-ci-zap tool is still pointing to an old account, which has been taken over by a security researcher and has a pseudo-malicious version of the app living there (it just pings their server when someone uses the tool and passes over environment variables).  The correct repo is updated in this PR.

CleanupAfterDocker.ps1

@@ -52,7 +52,7 @@ stop-service docker
 Write-Host "Downloading Docker-Ci-Zap"
 $dockerCiZapExe = Join-Path $Env:TEMP "docker-ci-zap.exe"
 Remove-Item $dockerCiZapExe -Force -ErrorAction Ignore
-(New-Object System.Net.WebClient).DownloadFile("https://github.com/jhowardmsft/docker-ci-zap/raw/master/docker-ci-zap.exe", $dockerCiZapExe)
+(New-Object System.Net.WebClient).DownloadFile("https://github.com/moby/docker-ci-zap/raw/master/docker-ci-zap.exe", $dockerCiZapExe)
 Unblock-File -Path $dockerCiZapExe
 
 Write-Host "Running Docker-Ci-Zap on $dockerRootDir"