modify sudo and ordering, use set -e fail early
modify sudo and ordering, use set -e fail early

Avoid calling sudo 253 times if the first one gets Ctrl-C'd.
Tell the user that sudo is prompting, and why.
Move the OS sanity check to the front, pre ping.

pmenglund/serf,hashicorp/serf,pmenglund/serf,pmenglund/serf,hashicorp/serf,pmenglund/serf,hashicorp/serf,pmenglund/serf,pmenglund/serf,hashicorp/serf,hashicorp/serf