fix utf8mb4 / MySQL5.5 crap

config/initializers/mysql_utf8mb4.rb

@@ -0,0 +1,10 @@
+# https://github.com/rails/rails/issues/9855#issuecomment-28874587
+require 'active_record/connection_adapters/abstract_mysql_adapter'
+
+module ActiveRecord
+  module ConnectionAdapters
+    class AbstractMysqlAdapter
+      NATIVE_DATABASE_TYPES[:string] = { :name => "varchar", :limit => 191 }
+    end
+  end
+end