Merge pull request #582 from arenard/patch-1

Use of -p option of mkdir command to avoid message telling tmp/pids directory already exists...

resque.sh

-mkdir tmp/pids
+mkdir -p tmp/pids
 nohup bundle exec rake environment resque:work QUEUE=* RAILS_ENV=production PIDFILE=tmp/pids/resque_worker.pid & >> log/resque_worker.log 2>&1