handle git

env GIT_AUTHOR_NAME='Bryan C. Mills'
env GIT_AUTHOR_EMAIL='bcmills@google.com'
env GIT_COMMITTER_NAME=$GIT_AUTHOR_NAME
env GIT_COMMITTER_EMAIL=$GIT_AUTHOR_EMAIL

git init

at 2019-07-15T14:01:24-04:00
env GIT_AUTHOR_DATE=2019-07-15T13:59:34-04:00
git add go.mod v3pkg.go
git commit -a -m 'all: add go.mod with v3 path'
git branch -m master
git tag 'v3.0.0'

git show-ref --tags --heads
cmp stdout .git-refs

-- .git-refs --
a3eab1261b8e3164bcbde9171c23d5fd36e32a85 refs/heads/master
a3eab1261b8e3164bcbde9171c23d5fd36e32a85 refs/tags/v3.0.0
-- go.mod --
module vcs-test.golang.org/git/v3pkg.git/v3

go 1.13
-- v3pkg.go --
package v3pkg