ExerciseCheckerError => Add remove dangling error code

types/Dojo/ExerciseCheckerError.ts

@@ -5,7 +5,8 @@ enum ExerciseCheckerError {
     DOCKER_COMPOSE_DOWN_ERROR              = 203,
     EXERCISE_RESULTS_FOLDER_TOO_BIG        = 204,
     EXERCISE_RESULTS_FILE_SCHEMA_NOT_VALID = 206,
-    UPLOAD                                 = 207
+    UPLOAD                                 = 207,
+    DOCKER_COMPOSE_REMOVE_DANGLING_ERROR   = 208
 }