👇 Click on the image for a new way to code review
####
[![Review these changes using an interactive CodeSee Map](https://s3.us-east-2.amazonaws.com/maps.codesee.io/images/github/fullstorydev/grpcurl/341/12445c92/62dd924dd4183ec9bb5f8ee7e2f054f830429524.svg)](https://app.codesee.io/r/reviews?pr=341&src=https%3A%2F%2Fgithub.com%2Ffullstorydev%2Fgrpcurl)
#### Legend
Added flag that sets up ALTS credentials to connect to gRPC services using Application Layer Transport Security.
Reference: https://grpc.io/docs/languages/go/alts/ Fixes: #333