union_tabs 1.0.0+5

A nested TabBarView overscroll event unites outer TabBarView scroll event.

1.0.0+5

• support flutter 1.12, remove duplicate code.

1.0.0+4

• fix nested TabBarView overscrolling then scroll reversely, the UI stuck.

1.0.0+3

• add Demo Comments.

1.0.0+2

• Clear flutter warnings.

1.0.0+1

• A nested TabBarView overscroll event unites outer TabBarView scroll event.