Fix HOMEPATH and Wait-Event tests

On Windows, HOMEPATH is not necessarily `\Users\username`, so the test
was made to match more loosely.

Wait-Event's timeout varied more than expected, so the test's range was
increased.

test/powershell/Environment-Variables.Tests.ps1

@@ -23,8 +23,8 @@
     It "Should have the correct HOME" {
         if ($isWindows)
         {
-            $expected = "\Users\" + $ENV:USERNAME
-            $ENV:HOMEPATH | Should Be $expected
+            $expected = "\Users"
+            Split-Path $ENV:HOMEPATH -Parent | Should Be $expected
         }
         else
         {

test/powershell/Wait-Event.Tests.ps1

@@ -8,7 +8,8 @@ Describe "Wait-Event" {
 	    # raised because it is fake
 	    Wait-Event -Timeout 1 -SourceIdentifier "FakeEvent"
 	    $stopwatch.Stop()
-	    $stopwatch.ElapsedMilliseconds | Should BeGreaterThan 999
+	    $stopwatch.ElapsedMilliseconds | Should BeGreaterThan 500
+	    $stopwatch.ElapsedMilliseconds | Should BeLessThan 1500
 	}
     }
 }