When I try downloading Zap without sudo I get the other error (package github.com/LN-Zap/zapconnect: mkdir /home/admin/go/src/github.com: permission denied). I checked environment details again and they look to be the same, details below.
Okay, that's great. For some reason permissions are not working properly so we will have to do it in a bit insecure way. Use
sudo chmod -R 777 ~/go (this will allow every single user to modify the contents of folders and files inside go) and then run
go get -d github.com/LN-Zap/zapconnect. I am too sleepy to think of a better solution.