More Capistrano job adjustments

JIRA: https://jira.media.berkeley.edu/jira/browse/CLC-2055

Capistrano now happily runs the first couple of steps on all 3 servers. But after it does the migrate.sh (which is node 1 only) the list of servers mysteriously now includes only dev-01. I changed the last command (calcentral start) to parallel execution to see if the server list will heal itself.