Export/Ebics: Add Tests to validate against schemas and fix issues

Elwig/Models/Dtos/Transaction.cs

@@ -1,4 +1,5 @@
 using Elwig.Models.Entities;
+using System;
 using System.Collections.Generic;
 using System.Linq;
 
@@ -19,7 +20,7 @@ namespace Elwig.Models.Dtos {
                 .ToList();
         }
 
-        public static string FormatAmountCent(long cents) => $"{cents / 100}.{cents % 100:00}";
+        public static string FormatAmountCent(long cents) => $"{cents / 100}.{Math.Abs(cents % 100):00}";
 
         public static string FormatAmount(decimal amount) => FormatAmountCent((int)(amount * 100));
     }