go get with private github repo

go get with private github repo

1. If you are trying to `go get` a private repo, you need to be able to enter your `username` and `password` from the prompt. 
To get the prompt you need to enable the git terminal prompt.

    env GIT_TERMINAL_PROMPT=1 go get 'github.com/the-user/the-repo'
    
2. Because of 2FA you cannot use your password.  You need to generate an access token and enter that in the password field
instead (you will want to copy at the clipboard on the token generation page, b/c it will be long).  To generate the token, go 
to [https://github.com/settings/tokens/new](https://github.com/settings/tokens/new).  Or from the Github UI, 
` Setting - Developer Settings - Personal access tokens`

If you use your password instead of an access token, you will get

    remote: Invalid username or password.
    fatal: Authentication failed for 'https://github.com/the-user/the-repo'
    package github.com/movableink/go-go-common-go: exit status 128
    
3. If you want to update package, add -u option

    env GIT_TERMINAL_PROMPT=1 go get -u 'github.com/the-user/the-repo'