DatePicker: add test

DatePicker: clean code

DatePicker: fix panel style, #318

Improve Tree

Steps: add vertical-align: middle

alert.css should use variables for colours instead of hardcoded values

1. Add props: renderContent, highlightCurrent
2. Fix Bug: tree do not change when data changed

Unittest

Unittest

fix reset method

TimePicker: add unit test

Fix build common config

Menu: fix indexPath of undefined

Update package.json dependencies

fix input type

Popover: fix the arrow appears, fixed #412