添加认证提供者迁移

class CreateAuthenticationProviders < ActiveRecord::Migration
    def change
        create_table "authentication_providers", :force => true do |t|
            t.string   "name"
            t.datetime "created_at",                 :null => false
            t.datetime "updated_at",                 :null => false
        end
        add_index "authentication_providers", ["name"], :name => "index_name_on_authentication_providers"
        AuthenticationProvider.create(name: 'facebook')
        AuthenticationProvider.create(name: 'twitter')
        AuthenticationProvider.create(name: 'gplus')
        AuthenticationProvider.create(name: 'linkedin')
    end
end