Log purge command

[tonglil]

Need to test still, waiting for drone/drone-go#35.
If there is a way to test it without that merge, let me know.

Closes https://github.com/drone/drone-cli/issues/76.

[tonglil]

PTAL @bradrydzewski

[tonglil]

Do you need to tag a release of the Go library in order for this to use it?

[bradrydzewski]

You can add a revision constraint to the Gopkg.toml and then run dep ensure which should update the vendored dependencies.

We should definitely use tags, but I think we need to revisit the tagging strategy for drone-go and drone-cli. We were previously trying to use the same tags as drone/drone, but this is not working well in my opinion, since they follow different release schedules.

[tonglil]

Alright, just built this locally and tested it, it was able to purge the logs.

Let me know if that toml file change is ok, or if you want me to pin to some commit sha.

[tonglil]

^ build failure is due to outdated merge ref.

[bradrydzewski]

@tonglil hey, sorry, looks like I might have caused a merge conflict when I updated to a newer version of drone-go. Can you update your PR and I can get this merged today? Thanks!!

[tonglil]

Updated

[bradrydzewski]

awesome, thanks again!