Add payment structure

spec/models/list_payment_spec.rb

@@ -0,0 +1,21 @@
+require 'spec_helper'
+
+describe ListPayment do
+  it "does completes a list if amount is equal to the list amount" do
+    list = create :list, price: 10.22
+    create :list_payment, amount: 10.22, list: list
+    list.should be_closed
+  end
+  it "does completes a list if amount is greater than the list amount" do
+    list = create :list, price: 10.22
+    create :list_payment, amount: 12, list: list
+    list.should be_closed
+  end
+  it "does completes a list if amount is less than the list amount, but total payments on list bigger" do
+    list = create :list, price: 10.22
+    create :list_payment, amount: 7, list: list
+    list.should be_active
+    create :list_payment, amount: 7, list: list
+    list.should be_closed
+  end
+end