Update setup_linux.sh

[Adrianzo]

for Fedora users :3

[blahah]

@Adrianzo thanks for this contribution. I think it's a good idea to support building on Fedora - but perhaps we should make it a separate script? i.e. instead of the current script setup_linux.sh we should have:

• setup_debian.sh
• setup_fedora.sh

that way, there's a simple runnable script for each distribution (and if people want to contribute more, that's great)

thoughts?