@Override
  public TaskExecution evaluate(TaskExecution aJobTask, Context aContext) {
    Map<String, Object> map = aJobTask.asMap();
    Map<String, Object> newMap = evaluateInternal(map,aContext);
    return SimpleTaskExecution.of(newMap);
  }
a {@link TaskEvaluator} implemenation which is based on 
Spring Expression Language for resolving expressions.

@author Arik Cohen
@since Mar 31, 2017
src/main/java/com/creactiviti/piper/core/task/SpelTaskEvaluator.java