Installation failures and https

[Ola Fosheim Grøstad]

I think one should try to test the installation procedures of 
downloads on dlang.org. The installation script fails on Os-X 
because GPG is not available, please consider using SHA instead 
with the fingerprint available from a https url, or use more than 
one method.

Also, the download.dlang.org subset is not available as https, 
dlang.org itself uses https, but not the 
http://downloads.dlang.org/releases/2.x/2.089.0/ .  traceroute 
lists a looooong list of servers, so this could be a potential 
issue.

Roadbumps like these are enough to loose new users before they 
even got started.

In comparison rust installs flawlessly using: curl --proto 
'=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh