Add Newman tool (#1185)

* Add Newman

* Move installation to NodeLts script on Windows

images/win/scripts/Installers/Install-NodeLts.ps1

@@ -33,3 +33,4 @@ npm install -g --save-dev webpack webpack-cli
 npm install -g yarn
 npm install -g lerna
 npm install -g node-sass
+npm install -g newman

images/win/scripts/Installers/Validate-NodeLts.ps1

@@ -35,3 +35,13 @@ else
     Write-Host "lerna is not on path"
     exit 1
 }
+
+if (Get-Command -Name 'newman')
+{
+    Write-Host "Newman $(newman --version) is on the path."
+}
+else
+{
+    Write-Host "Newman is not on the path."
+    exit 1
+}