adapt tests

spec/integration/articles_spec.rb

@@ -80,11 +80,13 @@ feature ArticlesController do
     describe "handles missing data" do
       it do
         find('input[type="submit"]').click # to overview
+        element = find('#new_articles__price')
+        element.fill_in with: ""
         find('input[type="submit"]').click # missing category, re-show form
         expect(find('tr.alert')).to be_present
         expect(supplier.articles.count).to eq 0
 
-        all("tr select > option")[1].select_option
+        element.fill_in with: 5.56
         find('input[type="submit"]').click # now it should succeed
         expect(supplier.articles.count).to eq 1
       end