rename factory_girl_(rails) to factory_bot_(rails)

spec/helpers/admin/dashboard_helper_spec.rb

@@ -8,7 +8,7 @@ describe Admin::DashboardHelper do
   end
 
   describe '#docker_data' do
-    before(:each) { FactoryGirl.create(:ruby) }
+    before(:each) { FactoryBot.create(:ruby) }
 
     it 'contains an entry for every execution environment' do
       expect(docker_data.length).to eq(ExecutionEnvironment.count)

spec/helpers/exercise_helper_spec.rb

@@ -2,7 +2,7 @@ require 'rails_helper'
 
 describe ExerciseHelper do
   describe '#embedding_parameters' do
-    let(:exercise) { FactoryGirl.build(:dummy) }
+    let(:exercise) { FactoryBot.build(:dummy) }
 
     it 'contains the locale' do
       expect(embedding_parameters(exercise)).to start_with("locale=#{I18n.locale}")