toolbar  z-index修改
[bugfix] remove export
Merge remote-tracking branch 'origin/dev-2.0.0' into dev-2.0.0
Merge pull request #8 from tianlili/dev-2.0.0

[testcase]补充barChart的用例
tabs的nav去掉分层样式，影响active样式更新！
[testcase]补充tabs的用例