Changes to xSQLServerSetup

Added a note to the README.md saying that it is not possible to add or remove features from a SQL Server failover cluster (issue dsccommunity#433).
Changed so that it reports false if the desired state is not correct (issue dsccommunity#432).

DSCResources/MSFT_xSQLServerSetup/MSFT_xSQLServerSetup.psm1

@@ -953,7 +953,7 @@ function Set-TargetResource
         # Get the disk resources that are available (not assigned to a cluster role)
         $availableStorage = Get-CimInstance -Namespace 'root/MSCluster' -ClassName 'MSCluster_ResourceGroup' -Filter "Name = 'Available Storage'" |
                                 Get-CimAssociatedInstance -Association MSCluster_ResourceGroupToResource -ResultClassName MSCluster_Resource | `
-                                Add-Member -MemberType NoteProperty -Name 'IsPossibleOwner' -Value $false -PassThru
+                                    Add-Member -MemberType NoteProperty -Name 'IsPossibleOwner' -Value $false -PassThru
 
         # First map regular cluster volumes
         foreach ($diskResource in $availableStorage)
@@ -1651,11 +1651,10 @@ function Test-TargetResource
     $getTargetResourceResult = Get-TargetResource @getTargetResourceParameters
     New-VerboseMessage -Message "Features found: '$($getTargetResourceResult.Features)'"
 
-    $result = $false
+    $result = $true
+
     if ($getTargetResourceResult.Features )
     {
-        $result = $true
-
         foreach ($feature in $Features.Split(","))
         {
             # Given that all the returned features are uppercase, make sure that the feature to search for is also uppercase
@@ -1668,13 +1667,15 @@ function Test-TargetResource
             }
         }
     }
+    else
+    {
+        $result = $false
+    }
 
     if ($PSCmdlet.ParameterSetName -eq 'ClusterInstall')
     {
         New-VerboseMessage -Message "Clustered install, checking parameters."
 
-        $result = $true
-
         $boundParameters.Keys | Where-Object {$_ -imatch "^FailoverCluster"} | ForEach-Object {
             $variableName = $_
 
@@ -1685,7 +1686,7 @@ function Test-TargetResource
         }
     }
 
-    $result
+    return $result
 }
 
 <#

README.md

@@ -887,6 +887,9 @@ Installs SQL Server on the target node.
     * ASSysAdminAccounts
     * AsSvcAccount
 
+> **Note:** It is not possible to add or remove features to a SQL Server failover cluster. This is a limitation of SQL Server.
+> See article [You cannot add or remove features to a SQL Server 2008, SQL Server 2008 R2, or SQL Server 2012 failover cluster](https://support.microsoft.com/en-us/help/2547273/you-cannot-add-or-remove-features-to-a-sql-server-2008,-sql-server-2008-r2,-or-sql-server-2012-failover-cluster).
+
 #### Parameters
 
 * **[String] Action** _(Write)_: The action to be performed. Defaults to 'Install'. *Note: AddNode is not currently functional.* { _Install_ | InstallFailoverCluster | AddNode | PrepareFailoverCluster | CompleteFailoverCluster }