overlay_support 1.0.5-hotfix1

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

[1.0.5-hotfix1] - 20201/2/9

• remove the deprecated method which from v1.12.x in BuildContext , fix #64

[1.0.5] - 2020/7/20

• Expose duration to showSimpleNotification #46 by Elvis Sun

[1.0.4] - 2020/5/26

• Support for BottomSlideNotification. #40 by Giles Correia Morton
• Upgrade min dart sdk version to 2.1.0. Policy

[1.0.3] - 2020/3/13

• expose toastTheme. by juvs

[1.0.2] - 2019/10/23

• fix Toast hidden behind ime #20

[1.0.1] - 2019/7/26

• swipe to dismiss #16
• adjust default toast background #18

[1.0.0] - 2019/6/16

• do not need pass context parameter to popup overlay

[0.3.0] - 2019/5/22

• add key parameter for showOverlay

[0.2.0] - 2019/5/15

• fix: call NotificationEntry#dismiss immediately when we showNotification cause an exception

[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