Release Splice version 3.0.0-alpha.16.
Release Splice version 3.0.0-alpha.16.

 * Use new Trampoline class. Closes #150.
 * Upgrade `riffle` to `2.0.0-alpha.29`. Closes #149.
 * Upgrade `b-tree` to `2.0.0-alpha.46`. Closes #148.
 * Upgrade `destructible` to `7.0.0-alpha.11`. Closes #147.
 * Upgrade `twiddle` to `2.0.0-alpha.6`. Closes #146.
 * Remove caret pin from alpha dependencies. Closes #145.

Closes #151.

bigeasy/splice,bigeasy/splice