include daemons gem

Gemfile

@@ -41,6 +41,7 @@ gem 'cityhash'
 gem 'bigquery', :git => "https://github.com/abronte/BigQuery.git", :ref => "b92b4e0b54574e3fde7ad910f39a67538ed387ad"
 gem 'memcache_mock'
 gem 'memoist'
+gem 'daemons'
 
 # needed for looser jpeg header compat
 gem 'ruby-imagespec', :require => "image_spec", :git => "https://github.com/r888888888/ruby-imagespec.git", :branch => "exif-fixes"

Gemfile.lock

@@ -107,6 +107,7 @@ GEM
     coderay (1.1.1)
     colorize (0.7.7)
     crass (1.0.2)
+    daemons (1.2.3)
     dalli (2.7.6)
     delayed_job (4.1.2)
       activesupport (>= 3.0, < 5.1)
@@ -380,6 +381,7 @@ DEPENDENCIES
   capistrano-rbenv
   capistrano3-unicorn
   cityhash
+  daemons
   dalli
   delayed_job
   delayed_job_active_record