use manager to manage ToastFuture

add a method dismissAllToast to dismiss all toast.

add a param with showToast to dismiss other toast.

add new params to helper user listen toast dismiss

showToast and showToastWidget will return ToastFuture the toastFuture call dismiss() to dismiss toast.

oktoast support page level.

you can use oktoast wrap your Scaffold.

use BuildContext cache. then showToast not need context, you can use the showToast in anywhere.

support flutter sdk 0.10 ,fix bug

update the textAlign : TextAlign.center
update the overflow: TextOverflow.ellipsis,

fix defaultPosition is invalid.

update readme

update readme

now libray is oktoast

stable version

the toast can set position

1. showToast
2. defaultPosition

add the textStyle radius backgroundColor

init commit