[Linaro-validation] Board failure

Just the one since Saturday:

---------------- snowball06 ---------------- http://validation.linaro.org/lava-server/scheduler/job/38435

As noted by Andy, this is our most flakey snowball. I'm proposing retiring it. It failed three times to reboot and get the network up. I went on the board and had to hard reset to get the network to come up, which suggests it gets into a weird state that needs a completely clean boot.

If it's not reliable it should be taken out. We can move it over to staging for more validation of reliability tests.

Thanks

Dave