Fixed wrong translation and superfluous visible flag

in step definition

config/locales/de.yml

@@ -76,7 +76,7 @@ de:
   caption_materials: "Stücke"
   caption_rate_history: "Stundensatz-Historie"
   caption_rate_history_for: "Stundensatz-Historie für %{user}"
-  caption_rate_history_for_project: "Studensatz-Historie für %{user} in Projekt %{project}"
+  caption_rate_history_for_project: "Stundensatz-Historie für %{user} in Projekt %{project}"
   caption_save_rate: "Satz speichern"
   caption_set_rate: "Aktuellen Satz festlegen"
   caption_show_locked: "Gesperrte Typen anzeigen"

features/step_definitions/cost_type_steps.rb

@@ -19,7 +19,7 @@ When(/^I delete the cost type "(.*?)"$/) do |name|
   ct = CostType.find_by_name name
 
   within ("#delete_cost_type_#{ct.id}") do
-    find('input[type=image]', :visible => true).click
+    find('input[type=image]').click
   end
 
   if page.driver.is_a? Capybara::Selenium::Driver