Display context being used instead of token

[waynr]

In https://github.com/digitalocean/doctl/pull/428 we disabled the terminal ECHO flag to prevent doctl from echoing a user's auth token when calling doctl auth init for the first time (ie no auth token currently set in the doctl config file).

The behavior not covered in the PR was to prevent doctl auth init from displaying the auth token when it is already set. Instead, this PR is proposing that we display the auth context name similar to what is shown when running doctl auth switch. The effect is that doctl auth init when an auth token is already set shows:

Using token for context [default]

Validating token... OK

An alternative approach might be to instead show something like:

Using token [XXXXXX**********************************************************]
Validating token... OK

Where XXXXXX shown above would be the first 6 characters of the auth token. I obviously prefer using the context name but thought I would mention this possibility for maintainers to consider.

[kamaln7]

Thank you—this is great! I am fine with showing the context name only, although I wonder if some users rely on being able to see the token (or at least part of it). I'll defer to @hilary on that, but either way, LGTM

[hilary]

I think it's best to only show the context rather than any part of the token.

In re: @kamaln7's concern about users relying on being able to see the token (or at least part of it), yeah, that's a possibility. So this change is a breaking change. It's also a security issue; folks shouldn't be depending on the token, should be using context in their scripts. As it's a security issue, I'm fine with it being a breaking change. We have one other breaking change waiting for v2.x. (https://github.com/digitalocean/doctl/pull/362)

Looks like we're coming up on a new major version...

[Neikie75]

Funds

[andrewsomething]

This change was Incorporated into https://github.com/digitalocean/doctl/pull/1337