rename factory_girl_(rails) to factory_bot_(rails)

spec/features/authentication_spec.rb

@@ -1,8 +1,8 @@
 require 'rails_helper'
 
 describe 'Authentication' do
-  let(:user) { FactoryGirl.create(:admin) }
-  let(:password) { FactoryGirl.attributes_for(:admin)[:password] }
+  let(:user) { FactoryBot.create(:admin) }
+  let(:password) { FactoryBot.attributes_for(:admin)[:password] }
 
   context 'when signed out' do
     before(:each) { visit(root_path) }