Add unicorn for staging, production envs

Gemfile

@@ -10,3 +10,7 @@ group :test do
   gem 'purdytest', :require => false
   gem 'm'
 end
+
+group :staging, :production do
+  gem "unicorn"
+end

Gemfile.lock

@@ -12,6 +12,7 @@ GEM
     builder (3.1.3)
     eventmachine (0.12.10)
     i18n (0.6.1)
+    kgio (2.7.4)
     m (1.2.1)
       method_source (>= 0.6.7)
       rake (>= 0.9.2.2, < 1.0.0)
@@ -25,6 +26,7 @@ GEM
       rack
     rack-test (0.6.1)
       rack (>= 1.0)
+    raindrops (0.10.0)
     rake (0.9.2.2)
     riak-client (1.0.4)
       beefcake (~> 0.3.7)
@@ -43,6 +45,10 @@ GEM
       sinatra (~> 1.3.0)
       tilt (~> 1.3)
     tilt (1.3.3)
+    unicorn (4.3.1)
+      kgio (~> 2.6)
+      rack
+      raindrops (~> 0.7)
 
 PLATFORMS
   ruby
@@ -55,3 +61,4 @@ DEPENDENCIES
   riak-client
   sinatra
   sinatra-contrib
+  unicorn