chore: release 1.2.0 (#95)

It appears we lost the feat/fix information provided in daa0d64 so the generated release version number in #77 is incorrect. 

This PR is intentionally empty. (see https://github.com/googleapis/release-please#how-do-i-change-the-version-number)

Release-As: 1.2.0

Author: busunkim96