rework module, add -WhatIf support and pipeline

.gitignore

@@ -0,0 +1,2 @@
+/bin
+.vscode

AzureADLicensing.build.ps1

@@ -0,0 +1,67 @@
+#Requires -Modules @{ModuleName='InvokeBuild';ModuleVersion='3.2.1'}
+#Requires -Modules @{ModuleName='PowerShellGet';ModuleVersion='1.6.0'}
+#Requires -Modules @{ModuleName='Pester';ModuleVersion='4.1.1'}
+#Requires -Modules @{ModuleName='ModuleBuilder';ModuleVersion='1.0.0'}
+
+$Script:IsAppveyor = $null -ne $env:APPVEYOR
+$Script:ModuleName = Get-Item -Path $BuildRoot | Select-Object -ExpandProperty Name
+Get-Module -Name $ModuleName | Remove-Module -Force
+
+task Clean {
+    Remove-Item -Path ".\Bin" -Recurse -Force -ErrorAction SilentlyContinue
+}
+
+task TestCode {
+    Write-Build Yellow "`n`n`nTesting dev code before build"
+    $TestResult = Invoke-Pester -Script "$PSScriptRoot\Test\Unit" -Tag Unit -Show 'Header','Summary' -PassThru
+    if($TestResult.FailedCount -gt 0) {throw 'Tests failed'}
+}
+
+task CompilePSM {
+    Write-Build Yellow "`n`n`nCompiling all code into single psm1"
+    try {
+        $BuildParams = @{}
+        if((Get-Command -ErrorAction stop -Name gitversion)) {
+            $GitVersion = gitversion | ConvertFrom-Json | Select-Object -Expand FullSemVer
+            $GitVersion = gitversion | ConvertFrom-Json | Select-Object -Expand InformationalVersion
+            $BuildParams['SemVer'] = $GitVersion
+        }
+    }
+    catch{
+        Write-Warning -Message 'gitversion not found, keeping current version'
+    }
+    Push-Location -Path "$BuildRoot\Source" -StackName 'InvokeBuildTask'
+    $Script:CompileResult = Build-Module @BuildParams -Passthru
+    Get-ChildItem -Path "$BuildRoot\license*" | Copy-Item -Destination $Script:CompileResult.ModuleBase
+    Pop-Location -StackName 'InvokeBuildTask'
+}
+
+task MakeHelp -if (Test-Path -Path "$PSScriptRoot\Docs") {
+
+}
+
+task TestBuild {
+    Write-Build Yellow "`n`n`nTesting compiled module"
+    $Script =  @{Path="$PSScriptRoot\test\Unit"; Parameters=@{ModulePath=$Script:CompileResult.ModuleBase}}
+    $CodeCoverage = (Get-ChildItem -Path $Script:CompileResult.ModuleBase -Filter *.psm1).FullName
+    $TestResult = Invoke-Pester -Script $Script -CodeCoverage $CodeCoverage -Show None -PassThru
+
+    if($TestResult.FailedCount -gt 0) {
+        Write-Warning -Message "Failing Tests:"
+        $TestResult.TestResult.Where{$_.Result -eq 'Failed'} | ForEach-Object -Process {
+            Write-Warning -Message $_.Name
+            Write-Verbose -Message $_.FailureMessage -Verbose
+        }
+        throw 'Tests failed'
+    }
+
+    $CodeCoverageResult = $TestResult | Convert-CodeCoverage -SourceRoot "$PSScriptRoot\Source" -Relative
+    $CodeCoveragePercent = $TestResult.CodeCoverage.NumberOfCommandsExecuted/$TestResult.CodeCoverage.NumberOfCommandsAnalyzed*100 -as [int]
+    Write-Verbose -Message "CodeCoverage is $CodeCoveragePercent%" -Verbose
+    $CodeCoverageResult | Group-Object -Property SourceFile | Sort-Object -Property Count | Select-Object -Property Count, Name -Last 10
+}
+
+task . Clean, TestCode, Build
+
+task Build CompilePSM, MakeHelp, TestBuild
+

README.md

@@ -2,16 +2,19 @@
 
 PowerShell Cmdlets to manage Azure AD Group based licensing.
 
-[![PSGallery Version](https://img.shields.io/powershellgallery/v/AzureADLicensing.svg?style=flat-square&label=PSGallery%20Version)](https://www.powershellgallery.com/packages/AzureADLicensing) [![PSGallery Downloads](https://img.shields.io/powershellgallery/dt/AzureADLicensing?style=flat-square&label=PSGallery%20Downloads)](https://www.powershellgallery.com/packages/AzureADLicensing)
+[![PowerShell Gallery Version](https://img.shields.io/powershellgallery/v/AzureADLicensing?label=PS%20Gallery%20Version&style=flat-square)](https://www.powershellgallery.com/packages/AzureADLicensing) [![PowerShell Gallery](https://img.shields.io/powershellgallery/dt/AzureADLicensing?label=PS%20Gallery%20downloads&style=flat-square)](https://www.powershellgallery.com/packages/AzureADLicensing) ![GitHub](https://img.shields.io/github/license/nicolonsky/AzureADLicensing?style=flat-square)
 
 ## Using the module
 
 1. Install the module: ```Install-Module -Name AzureADLicensing -AllowClobber```
-2. If you hav the deprecated AzureRM module installed, uninstall it first ```Uninstall-AzureRm```
-3. Authenticate to Azure: ```Connect-AzAccount```
+2. If you have the deprecated AzureRM module installed, uninstall it first ```Uninstall-AzureRm```
+3. Authenticate to your Azure tenant: ```Connect-AzAccount```
+    1. Feel free to use a service principal for unattended authentication and automation
 
 ## Available commands
 
+All critical commands which modify settings support the `-WhatIf` parameter to predict changes.
+
 Get available licenses and services:
 
 <pre>