Actually support creating assets

src/main/java/be/seeseepuff/pcinv/models/RamAsset.java

@@ -31,7 +31,7 @@ public class RamAsset implements Asset
 	/// The capacity of the RAM in bytes.
 	@Property("Capacity")
 	@Capacity
-	private long capacity;
+	private Long capacity;
 
 	/// The type of memory. E.g.: DDR2, SDRAM, ISA-8, etc...
 	@Property("Type")