nContainer module should not require Containers

[KarolKaczmarek]

nContainer.psd1 contains

# Modules that must be imported into the global environment prior to importing this module
RequiredModules = @('Containers')

Containers should not be required since the machine may not have this feature enabled. In that case, even if we try to apply configuration which installs this feature:

configuration ContainerSetup
{
    [CmdletBinding()]
    param(
        [Parameter(Mandatory=$true, Position=0, ValueFromPipeline=$true)]
        [string] 
        $ContainerName
    )

    Import-DscResource -ModuleName PSDesiredStateConfiguration -Name WindowsFeature
    Import-DscResource -ModuleName nContainer

    WindowsFeature ContainersFeature
    {
        Name =   'Containers'
        Ensure = 'Present'
    }

    nContainer Container
    {
        Name      = $ContainerName
        ImageName = 'WindowsServerCore'
        Ensure    = 'Present'
        State     = 'Off'
        VirtualSwitchName = 'Virtual Switch'
    }
} 

PowerShell will try to load Containers module during parsing the configuration which results in a failure:

PS C:\Packages\Plugins\Microsoft.Powershell.DSC\2.8.0.0\DSCWork\CreateContainer.ps1.0> Start-DscConfiguration -path .\Co
ntainerSetup\ -Wait -force
Importing module nContainer failed with error - The required module 'Containers' is not loaded. Load the module or
remove the module from 'RequiredModules' in the file 'C:\Program
Files\WindowsPowerShell\Modules\nContainer\nContainer.psd1'.
    + CategoryInfo          : InvalidOperation: (root/Microsoft/...gurationManager:String) [], CimException
    + FullyQualifiedErrorId : ImportModuleFailed
    + PSComputerName        : localhost