Make Ethstats instance deploy optional

@kvhnuke Deploying a single instance on AWS is very expensive and some might not need the additional ethstats server for viewing their nodes. ( Or we can use the public ethstats instance like https://ethstats.net )

[kvhnuke]

I hope this helps https://github.com/MyEtherWallet/docker-geth-lb/blob/master/aws-cloudformation/parity-deployment-remote-ethstats.json

That's the parity version, that one won't deploy an extra ethstats server. You can also set the IP or the address of a public one. I'll do the same for get soon :)

@kvhnuke Right and we can set geth for not deploying an extra ethstats server also 😄 Or we can use the internal ethstats api on geth ( by adding --ethstats option back on geth command ).

[kvhnuke]

I didn't even know about --ethstats I'll add and update the geth builds with that
Thank you!