added token to users model and generate token method to users controller

app/models/user.rb

@@ -81,5 +81,11 @@ private
       end
     end
   end
+  
+  def generate_token(column)
+    begin
+      self[column] = SecureRandom.urlsafe_base64
+    end while User.exists?(column => self[column])
+  end
 
 end

db/migrate/20140312002642_add_auth_token_to_users.rb

@@ -0,0 +1,5 @@
+class AddAuthTokenToUsers < ActiveRecord::Migration
+  def change
+    add_column :users, :auth_token, :string
+  end
+end

db/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended to check this file into your version control system.
 
-ActiveRecord::Schema.define(:version => 20131113200708) do
+ActiveRecord::Schema.define(:version => 20140312002642) do
 
   create_table "benefits", :force => true do |t|
     t.datetime "created_at", :null => false
@@ -83,6 +83,7 @@ ActiveRecord::Schema.define(:version => 20131113200708) do
     t.integer  "user_id"
     t.datetime "created_at", :null => false
     t.datetime "updated_at", :null => false
+    t.string   "auth_token"
   end
 
   create_table "work_infos", :force => true do |t|