CLC-1111 Warm up the app at end of Capistrano deploy script, for each se...

...rver

JIRA: https://jira.media.berkeley.edu/jira/browse/CLC-1111

Yu-Hung and I discovered that removing the maintenance page (done as part of the Capistrano deploy.rb) causes the Rails app to restart, which moots the warming-up we did in start-trinidad.sh. So with this commit we'll warm up after removing the maint page. We still need to warm up in start-trinidad.sh, because some environments (prod, qa) don't use Capistrano.