fix indexing and ordering for section and card

spec/models/merged/card_spec.rb

@@ -13,5 +13,14 @@ module Merged
     it "has index" do
       expect(first.index).to eq 1
     end
+
+    it "first has no previous" do
+      expect(first.index).to be 1
+      expect(first.previous_card).to be nil
+    end
+    it "first has next" do
+      expect(first.next_card.index).to be 2
+    end
+
   end
 end

spec/models/merged/page_spec.rb

@@ -18,7 +18,7 @@ module Merged
     end
     it "has section indexes" do
       index.sections.each_with_index do |section, index|
-        expect(section.index).to be index + 1
+        expect(section.index).to be index + 1 # because we have human index
       end
     end
   end