Randomize the author list on request; keep the zowners.go file stable so
a 'go generate' remain stable.

chaos.Owners could potentially be a map and be randomized by ranging
over it, but this seems simpler and fewer lines of code.

Bit of Easter hacking; seems more fair to randomize this list.
Signed-off-by: Miek Gieben <miek@miek.nl>