Suggestion - Add proxy support #490

I was behind a proxy here and I had to change the script to add "-Proxy $Proxy -ProxyCredential $MyCreds" at the end of each "Invoke-WebRequest" cmdlet.

Same thing for "Install-PackageProvider -Name NuGet"

But then, i got error with "Find-DscResource -moduleName $modulename -RequiredVersion $moduleversion | Save-Module -Path "$PSScriptRoot\Temp\DSC"

I've search a long time and try these configuration without success :

Setting TLS 1.2 : [Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12
Bypassing the certificate validation : [Net.ServicePointManager]::ServerCertificateValidationCallback = {$true};
Bypassing the certificate validation by code instead of block :
#C# class to create callback
$code = @"
public class SSLHandler
{
public static System.Net.Security.RemoteCertificateValidationCallback GetSSLHandler()
{

    return new System.Net.Security.RemoteCertificateValidationCallback((sender, certificate, chain, policyErrors) => { return true; });
}

}
"@
#compile the class
Add-Type -TypeDefinition $code

#disable checks using new class
[System.Net.ServicePointManager]::ServerCertificateValidationCallback = [SSLHandler]::GetSSLHandler()

No success!! but then i've found way to configure default proxy but i wasnt able to add it to the script, and I had to install the module outside of the "Prereq" script. here what I use for this to work :

$proxy = 'YER PROXY HERE' # update this
[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12
[system.net.webrequest]::defaultwebproxy = new-object system.net.webproxy($proxy)
[system.net.webrequest]::defaultwebproxy.credentials = [System.Net.CredentialCache]::DefaultNetworkCredentials
[system.net.webrequest]::defaultwebproxy.BypassProxyOnLocal = $true

Install-PackageProvider -Name nuget -Scope AllUsers -Confirm:$false -Force -MinimumVersion 2.8.5.201
Register-PSRepository -Default -verbose

Install-Module -Name xActiveDirectory -Scope AllUsers -Confirm:$false -Force
Install-Module -Name xDHCpServer -Scope AllUsers -Confirm:$false -Force
Install-Module -Name xDNSServer -Scope AllUsers -Confirm:$false -Force
Install-Module -Name NetworkingDSC -Scope AllUsers -Confirm:$false -Force
Install-Module -Name xPSDesiredStateConfiguration -Scope AllUsers -Confirm:$false -Force

Probably there more "code head" people who can help with this since it's ugly but working :)

Thanks again for the great script!