Introduce notary reset command from notary status flags

[riyazdf]

Factors out the --reset and --unstage flags from notary status into a new notary reset command.
The notary status command now does not have any flags and cannot mutate any state.

• notary reset <GUN> --all resets all staged changes for a gun
• notary reset <GUN> -n 1 -n 2 resets the change items numbered 1 and 2 from notary status <GUN>

Signed-off-by: Riyaz Faizullabhoy riyaz.faizullabhoy@docker.com

[cyli]

Non-blocking nitpick: Wondering if notary reset GUN # # # and notary reset GUN --all would make sense? Alternately, notary reset GUN -n 1 -n 2 to remove specific ones? Just because reset and unstage are sort of similar words to me, it just sounds odd to use one as the flag for the other.

[riyazdf]

@cyli: agreed! notary reset GUN -n 1 -n 2 and notary reset GUN --all make much more sense in the context of this new command. I'll update this 👍

[cyli]

Awesome, thanks for fixing this! LGTM

[endophage]

LGTM