reorderables 0.2.1

Reorderable table, row, column, wrap, sliver list that allow drag and drop of their children.

[0.2.1] - 28 April 2019.

• Bugfix: couldn't add/remove elements in ReorderableWrap.
• Bugfix: added elements weren't draggable in ReorderableSliverList.
• Merged pull request: flag to choose between long press draggable and the short one.

[0.2.0] - 5 March 2019.

• Added ReorderableSliverList, ReorderableSliverChildBuilderDelegate, and ReorderableSliverChildListDelegate.
• Bugfix: ReorderableFlex's animation.

[0.1.6] - 1 March 2019.

• Updated API references and README.
• Bugfix: made ReorderableTable's onReorder required.
• Bugfix: corrected scrollDirection in ReorderableRow.

[0.1.5] - 26 February 2019.

• Updated API references.

[0.1.4] - 25 February 2019.

• Alignment bugfix.
• Added column examples.