Add rails-i18n gem.

Gemfile

@@ -2,6 +2,7 @@ source 'https://rubygems.org'
 ruby "1.9.3"
 
 gem 'rails', '3.2.19'
+gem 'rails-i18n', '~> 3.0.0'
 
 gem 'pg'
 gem 'spree', :github => 'openfoodfoundation/spree', :branch => '1-3-stable'

Gemfile.lock

@@ -397,6 +397,9 @@ GEM
       activesupport (= 3.2.19)
       bundler (~> 1.0)
       railties (= 3.2.19)
+    rails-i18n (3.0.1)
+      i18n (~> 0.5)
+      rails (>= 3.0.0, < 4.0.0)
     railties (3.2.19)
       actionpack (= 3.2.19)
       activesupport (= 3.2.19)
@@ -568,6 +571,7 @@ DEPENDENCIES
   rack-livereload
   rack-ssl
   rails (= 3.2.19)
+  rails-i18n (~> 3.0.0)
   representative_view
   roadie-rails (~> 1.0.3)
   rspec-rails

app/mailers/spree/user_mailer_decorator.rb

@@ -2,6 +2,6 @@ Spree::UserMailer.class_eval do
   def signup_confirmation(user)
     @user = user
     mail(:to => user.email, :from => from_address,
-         :subject => 'Welcome to ' + Spree::Config[:site_name])
+         :subject => t(:welcome_to) + Spree::Config[:site_name])
   end
 end