back_button_interceptor 4.0.1

Back Button Interceptor. May be used to intercept the Android back-button, as an alternative to `WillPopScope`.

[1.0.0] - 02/01/2019

• Tested thoroughly. Single interceptor.

[2.0.0] - 02/01/2019

• Multiple interceptors.

[2.0.2] - 22/02/2019

• Fixed dart version.

[3.0.0] - 03/03/2019

Prevents silent errors swallowing.

[4.0.1] - 09/03/2019

Functions added last are fired first. Parameters ifNotYetIntercepted and zIndex.