node-tap strange behaviour cause CircleCI & Travis-CI keep failing

[huan]

Issue detail is posted here: tapjs/tapjs#272

Stackflow: http://stackoverflow.com/questions/38239735/strange-bug-in-circleci-travie-ci-docker-env-node-tap-js-pass-but-tap-tap-js
CircleCI Forum: https://discuss.circleci.com/t/strange-bug-in-circleci-docker-env-node-tap-js-pass-but-tap-tap-js-will-fail/5005

[huan]

switched tap to tape had already solved this problem.

now wechaty use ava as test runner.