Remove npm.ps1

Author: nirinchev

.evergreen/InstallNode.ps1

@@ -20,6 +20,7 @@ Get-ChildItem -Path $PSScriptRoot
 Set-Location -Path $node_dir
 Remove-Item .\npm
 Remove-Item .\npm.cmd
+Remove-Item .\npm.ps1
 Remove-Item .\npx
 Remove-Item .\npx.cmd
 Move-Item .\node_modules\npm -Destination .\node_modules\npm2