Add batch script to run all tests against PSv3 and PSv2

Invoke-AllTests.cmd

@@ -0,0 +1,13 @@
+cls
+
+powershell.exe -noprofile %~dp0TestGetPsGet.ps1
+@if errorlevel 1 echo FAIL & exit /b %errorlevel%
+
+powershell.exe -noprofile %~dp0Tests.ps1
+@if errorlevel 1 echo FAIL & exit /b %errorlevel%
+
+powershell.exe -version 2 -noprofile %~dp0TestGetPsGet.ps1
+@if errorlevel 1 echo FAIL & exit /b %errorlevel%
+
+powershell.exe -version 2 -noprofile %~dp0Tests.ps1
+@if errorlevel 1 echo FAIL & exit /b %errorlevel%

TestGetPsGet.ps1

@@ -9,7 +9,7 @@ function SimulateBootstrapDownload {
     Get-Content -Path $PSScriptRoot\GetPsGet.ps1 | Out-String 
 }
 
-Remove-Variable -Name PsGetDestinationModulePath
+Remove-Variable -Name PsGetDestinationModulePath -ErrorAction SilentlyContinue
 # backup current PSModulePath before testing
 $OriginalPSModulePath = $Env:PSModulePath