Use the prop-types package from npm instead.

[zhenizhui]

fix a warning

Warning: Accessing PropTypes via the main React package is deprecated. Use the prop-types package from npm instead.

and

add '.idea' to .gitignore

[mocheng]

先暂缓这个merge，prop-types虽然被分离出来了，但是依然可以从react包中导入。