Add id to each shipment

lib/planet_express_express/shipment_reader.rb

@@ -3,6 +3,7 @@ module PlanetExpressExpress
   class ShipmentReader
     def initialize(prices)
       @prices = prices
+      @id = 0
     end
 
     # Expects to read a file
@@ -46,7 +47,8 @@ module PlanetExpressExpress
       parts = line.split(" ")
 
       shipment = {
-        date: Date.parse(parts[0]),
+        id: sequential_id,
+        date: Date.strptime(parts[0], "%Y-%m-%d"),
         size: parts[1]&.to_sym,
         provider: parts[2]&.to_sym,
         price: 0,
@@ -62,5 +64,9 @@ module PlanetExpressExpress
 
       shipment
     end
+
+    def sequential_id
+      @id += 1
+    end
   end
 end