Add unicorn config.

Procfile

@@ -1,4 +1,4 @@
-web: bundle exec unicorn --host ${HOST:="127.0.0.1"} --port ${PORT:="8080"} --env ${RAILS_ENV:="development"}
+web: bundle exec unicorn --config-file config/unicorn.rb --host ${HOST:="127.0.0.1"} --port ${PORT:="8080"} --env ${RAILS_ENV:="development"}
 worker: bundle exec rake jobs:work
 backup: ./packaging/scripts/backup
 check: ./packaging/scripts/check

config/unicorn.rb

@@ -0,0 +1,3 @@
+worker_processes Integer(ENV["WEB_CONCURRENCY"] || 1)
+timeout 15
+preload_app false