ExerciseResultFile => All field are optional & Add container exit code information

helpers/Dojo/SharedExerciseHelper.ts

@@ -9,10 +9,12 @@ class SharedExerciseHelper {
         const ajv = new Ajv();
 
         const schema: JTDSchemaType<ExerciseResultsFile> = {
-            properties          : {
-                success: { type: 'boolean' }
-            },
+            properties          : {},
             optionalProperties  : {
+                success: { type: 'boolean' },
+
+                containerExitCode: { type: 'uint32' },
+
                 successfulTests: { type: 'uint32' },
                 failedTests    : { type: 'uint32' },
 

types/Dojo/ExerciseResultsFile.ts

 interface ExerciseResultsFile {
-    success: boolean;
+    success?: boolean;
+
+    containerExitCode?: number;
 
     successfulTests?: number;
     failedTests?: number;