新增3个测试
Merge branch 'master' of github.com:qifun/stateless-future-util into statelessFutureUtilTest
Merge branch 'master' of github.com:qifun/stateless-future-util into statelessFutureUtilTest
修正了JumpInto调用位置的错误导致Zip在一起的两个Future先后执行
新增PollTest的测试，同时测试了CancellablePromise的一些方法
Merge branch 'master' of github.com:qifun/stateless-future-util into statelessFutureUtilTest
针对Promise的completeWith函数的修改，修改了调用方式
Avoid inline completeWith