I have a very old Raspberry Pi B (not even B+) with a HiFiberry and wanted to stream Spotify to my audio set. Installed DietPi and then followed the very simple instructions from https://dtcooper.github.io/raspotify/
Basically you have to run this command
curl -sL https://dtcooper.github.io/raspotify/install.sh | sh
So simple and it runs perfectly! Just wanted to share this