Update golxc dependency
Merge pull request #420 from wallyworld/update-golxc-dependency

Update golxc dependency

Pull in golxc rev 12 to fix lp:1350011
action-set: a jujuc command for Actions to send values back to state

action-set permits action hooks to define an arbitrary map of params
which will be returned to the state server at the end of the Action.
actionComplete / actionFail in uniter
WIP: ActionCompleted / ActionFailed
Fixed for new action-set