Add source URL to test fixture script (#9296)

provisioner/powershell/test-fixtures/scripts/set_version_latest.ps1

@@ -1,13 +1,13 @@
+# Test fixture is a modified version of the example found at
+# https://www.powershellmagazine.com/2012/10/23/pstip-set-strictmode-why-should-you-care/
+
 Set-StrictMode -Version Latest
 $ErrorActionPreference = "Stop"
 
 $myNumbersCollection = 1..5
-
-if($myNumbersCollection -contains 3)
-{
+if($myNumbersCollection -contains 3) {
     "collection contains 3"
 }
-else
-{
+else {
     "collection doesn't contain 3"
 }