Add Unicorn server

Gemfile

@@ -1,10 +1,12 @@
 source "https://rubygems.org/"
+ruby "1.9.3"
 
 gem 'sinatra'
 gem 'haml'
 gem 'data_mapper'
 gem 'dm-postgres-adapter'
 gem 'pg'
+gem 'unicorn'
 
 group :development do
   gem 'shotgun'

Gemfile.lock

@@ -56,10 +56,12 @@ GEM
       tilt
     json (1.8.0)
     json_pure (1.8.0)
+    kgio (2.9.2)
     mime-types (1.23)
     multi_json (1.7.3)
     pg (0.15.1)
     rack (1.5.2)
+    raindrops (0.13.0)
     rest-client (1.6.7)
       mime-types (>= 1.16)
     sequel (3.20.0)
@@ -74,6 +76,10 @@ GEM
       sequel (~> 3.20.0)
       sinatra (~> 1.0.0)
     tilt (1.4.1)
+    unicorn (4.8.2)
+      kgio (~> 2.6)
+      rack
+      raindrops (~> 0.7)
     uuidtools (2.1.4)
 
 PLATFORMS
@@ -87,3 +93,4 @@ DEPENDENCIES
   shotgun
   sinatra
   taps
+  unicorn

config/unicorn.rb

@@ -0,0 +1,6 @@
+# http://datachomp.com/archives/using-unicorn-with-sinatra-or-padrino-on-heroku/
+# https://devcenter.heroku.com/articles/rails-unicorn
+
+worker_processes Integer(ENV["WEB_CONCURRENCY"] || 3)
+timeout 15
+preload_app true