>>751
これのどの行にそれを入れて　rake db:migrate を実行すればいいのでしょうか？

class DeviseCreateUsers < ActiveRecord::Migration
def self.up
create_table(:users) do |t|
t.database_authenticatable :null => false
t.recoverable
t.rememberable
t.trackable

# t.encryptable
t.confirmable
# t.lockable :lock_strategy => :failed_attempts, :unlock_strategy => :both
# t.token_authenticatable


t.timestamps
end

add_index :users, :email, :unique => true
add_index :users, :reset_password_token, :unique => true
add_index :users, :confirmation_token, :unique => true

# add_index :users, :unlock_token, :unique => true
# add_index :users, :authentication_token, :unique => true
end

def self.down
drop_table :users
end
end