Update rack dependency to version 1.2.3

Remove version number from Gemfile. Specific version numbers belong in
the manifest (Gemfile.lock) unless we need to direct bundler to use a
specific version for some reason (e.g. compatibility).

Gemfile

@@ -2,24 +2,24 @@ source 'http://rubygems.org'
 
 gem 'rails', '3.0.9'
 
-gem 'clearance',         '0.9.0.rc9'
+gem 'clearance',        '0.9.0.rc9'
 gem 'fog'
-gem 'gchartrb',          '0.8',   :require => 'google_chart'
-gem 'gravtastic',        '2.1.3'
-gem 'high_voltage',      '0.9.1'
-gem 'hoptoad_notifier',  '2.4.1'
+gem 'gchartrb',         '0.8',   :require => 'google_chart'
+gem 'gravtastic',       '2.1.3'
+gem 'high_voltage',     '0.9.1'
+gem 'hoptoad_notifier', '2.4.1'
 gem 'mail'
-gem 'newrelic_rpm',      '2.13.4'
-gem 'paul_revere',       '0.1.5'
+gem 'newrelic_rpm',     '2.13.4'
+gem 'paul_revere',      '0.1.5'
 gem 'pg'
-gem 'rack',  '1.2.2'
-gem 'rack-maintenance',  '0.3.0', :require => 'rack/maintenance'
-gem 'redis',             '2.1.1'
-gem 'rest-client',       '1.0.3', :require => 'rest_client'
-gem 'sinatra',           '1.2.1'
-gem 'will_paginate',     '3.0.pre2'
-gem 'xml-simple',        '1.0.12'
-gem 'yajl-ruby',         '0.8.2', :require => 'yajl/json_gem'
+gem 'rack'
+gem 'rack-maintenance', :require => 'rack/maintenance'
+gem 'redis',            '2.1.1'
+gem 'rest-client',      '1.0.3', :require => 'rest_client'
+gem 'sinatra',          '1.2.1'
+gem 'will_paginate',    '3.0.pre2'
+gem 'xml-simple',       '1.0.12'
+gem 'yajl-ruby',        '0.8.2', :require => 'yajl/json_gem'
 
 platforms :ruby_18 do
   gem 'system_timer'

Gemfile.lock

@@ -113,7 +113,7 @@ GEM
       rails (~> 3.0.0)
     pg (0.11.0)
     polyglot (0.3.1)
-    rack (1.2.2)
+    rack (1.2.3)
     rack-maintenance (0.3.0)
       rack (>= 1.0)
     rack-mount (0.6.14)
@@ -195,8 +195,8 @@ DEPENDENCIES
   nokogiri
   paul_revere (= 0.1.5)
   pg
-  rack (= 1.2.2)
-  rack-maintenance (= 0.3.0)
+  rack
+  rack-maintenance
   rack-test (= 0.5.7)
   rails (= 3.0.9)
   redgreen (= 1.2.2)