Extract registrar controller translations in admin area

#279

spec/features/admin/registrars/edit_spec.rb

@@ -0,0 +1,18 @@
+require 'rails_helper'
+
+RSpec.feature 'Edit registrar' do
+  given!(:registrar) { create(:registrar_with_unlimited_balance) }
+
+  background do
+    sign_in_to_admin_area
+  end
+
+  it 'updates registrar' do
+    visit admin_registrar_url(registrar)
+    click_link_or_button 'Edit'
+
+    click_link_or_button 'Update registrar'
+
+    expect(page).to have_text('Registrar has been successfully updated')
+  end
+end