public Task UpdateTask(int projectId, int storyId, int taskId, bool isCompleted, string text)
		{
			var path = string.Format("/projects/{0}/stories/{1}/tasks/{2}", projectId, storyId, taskId);
			var taskReq = new StoryTaskXmlRequest
				{
					description = text,
					complete = isCompleted ? "true" : "false"
				};

			var taskResp = this.RequestPivotal<StoryTaskXmlResponse>(path, taskReq, "PUT");
			return CreateTask(taskResp);
		}
		public Task AddTask(int projectId, int storyId, string text)
		{
			var path = string.Format("/projects/{0}/stories/{1}/tasks", projectId, storyId);
			var taskReq = new StoryTaskXmlRequest { description = text };

			var taskResp = this.RequestPivotal<StoryTaskXmlResponse>(path, taskReq, "POST");
			return CreateTask(taskResp);
		}