Interfaces file formatting

[DamienBth]

Despite all examples in debian documentation :

iface eth0 inet static
address 192.168.10.1
netmask 255.255.255.0

works exactly like :

iface eth0 inet static
        address 192.168.10.1
        netmask 255.255.255.0

And I can't find any rule about indentation. So I consider it like a convention not a norm. I think you should do the same and handle both ways. But the choice is yours.
https://github.com/dggreenbaum/debinterface/blob/master/interfacesReader.py#L81

PS : By the way, good job for this quite helpful tool :D