https://github.com/PowerShell/PowerShell/blob/master/tools/download.sh was not updated in alpha.12 release. We cannot update it now to alpha.13 because the Add-Type issue (#2764) is causing problem to PowerShellGet, and PowerShellGet repo is depending on this script to setup Travis test environment. So we need to update this file with alpha.14 after the issue is resolved in alpha.14 release.