You could try and use/add go modules to your cloned project (with Go 1.11+, and
go mod init github.com/kkdai/line-login-go go mod vendor
Then you should have all missing dependencies added to your vendor folder.
And you would not even need
As seen in kardianos/govendor/issue 424,
go mod should recognize
vendor/vendor.json and import the right references previously declared and managed by