bottom_tab_bar library

modify from https://github.com/flutter/flutter/blob/master/packages/flutter/lib/src/cupertino/bottom_tab_bar.dart lastest push: 2019.12.29 flutter v1.13.5

lastest commit: 2019.12.17 commit https://github.com/flutter/flutter/commit/449f4a6673f6d89609b078eb2b595dee62fd1c79 #45502 https://github.com/flutter/flutter/pull/45502

Classes

CupertinoTabBar
An iOS-styled bottom navigation tab bar. [...]