update heroku bundle to always include mysql

Gemfile

@@ -38,6 +38,7 @@ end
 
 group :heroku do
   gem 'pg'
+  gem 'mysql'
 end
 
 gem 'settingslogic', :git => 'https://github.com/binarylogic/settingslogic.git'

Gemfile.lock

@@ -243,6 +243,7 @@ GEM
       gem_plugin (>= 0.2.3)
     multi_json (1.0.4)
     multipart-post (1.1.4)
+    mysql (2.8.1)
     mysql2 (0.2.17)
     net-scp (1.0.4)
       net-ssh (>= 1.99.1)
@@ -455,6 +456,7 @@ DEPENDENCIES
   mobile-fu
   mock_redis
   mongrel
+  mysql
   mysql2 (= 0.2.17)
   newrelic_rpm
   nokogiri (~> 1.5.0)

Procfile

-web: bundle exec rails s -p $PORT
+web: bundle exec rails s thin -p $PORT
 redis: redis-server
 worker: QUEUE=* bundle exec rake resque:work