add cache configuration to 'actions/setup-node' (#570)
add cache configuration to 'actions/setup-node' (#570)

* ci: change the version specification of actions to v2

It seems to be better to specify v2.

* ci(cache): add cache configuration to `actions/setup-node`

https://github.com/actions/setup-node#caching-packages-dependencies
motdotla/node-lambda,motdotla/node-lambda