Add relation from Edition to Internships

src/InternshipSystem.Core/Edition.cs

@@ -10,5 +10,6 @@ namespace InternshipSystem.Core
         public DateTime EndDate { get; set; }
         public DateTime IPPDeadlineDate { get; set; }
         public List<InternshipProgramEntry> Subjects { get; set;}
+        public List<Internship> Internships { get; set; }
     }
 }