Cannot list just the nth account in a wallet

[dpetranek]

Describe the bug
If I want to see the third account I can do textile wallet accounts -d 3 <m>, but that shows me accounts 1-3. So I add an offset textile wallet accounts -d 3 -o 3 <m>, and now I see accounts 3-5. So I think what I'd want is textile wallet accounts -d 1 -o 3 <m> but that's not legal: offset must be greater than 0 and less than depth

To Reproduce
textile wallet accounts -d 1 -o 3 <m>

Note that you receive an error message instead of just one account.

Expected behavior
I would expect to see the only the third account.

[carsonfarmer]

We have this functionality now in https://github.com/textileio/js-textile-wallet. Perhaps we could provide the same API/functionality here?