* Add shared_options to readme command.
This makes --shallow and --format work again.
* Update yarn.lock based on package.json.
* Move readme example to where it works,
remove superfluous usage string.
yargs@>=7 throws exceptions on incorrectly structured builder objects.
* Update expected readme test fixture.
* Update bin-readme snapshot.
* s/_.assign/Object.assign/g thanks to node@>=4.
* Update yarn.lock based on package.json (lint-staged@6)
* Override flow error message.