shipjs prepare --retry

[eunjae-lee]

--retry

It prepares a PR for the latest version again.
It can be used when shipjs trigger somehow fails on CI, you add commits to fix it, and want to prepare a PR again.

It does the following extra things:

• Automatically uses the latest version. (Don't ask about next version)
• Delete local and remote branches: releases/vx.y.z
• Delete local and remote tag if exists.