overlay_support 0.1.0

proivder support for overlay, easy to build toast and internal notification

[0.1.0] - 2019/3/5

• expose showOverlay method to help build custom overlay
• mark autoDismiss param as Deprecate, replace by duration param

[0.0.4] - 2019/3/2

• bug fix

[0.0.3] - 2019/2/18

• bug fix

[0.0.2] - 2019/2/17

• remove line limit of toast

[0.0.1] - 2019/2/16

• support notification
• support toast