Add controller for Problems with index and show actions

db/seeds.rb

@@ -6,9 +6,14 @@
 #   cities = City.create([{ name: 'Chicago' }, { name: 'Copenhagen' }])
 #   Mayor.create(name: 'Emanuel', city: cities.first)
 
+Translation.delete_all
+Problem.delete_all
+
 for i in 1..103 do
-  Translation.create(
+  translation = Translation.create(
+             problem_id: i,
              title: "Problem Nummer #{i}",
              content: "Das hier ist der Inhalt von <b>Problem #{i}</b>.<br />Hier ist die zweite Zeile."
   )
-end
+  Problem.create(id: i, translation: translation)
+end