Feature/ssh

Hello Palantir,

We've recently started using stashbot at my job and I recently had the requirement to use ssh URLs for interacting with Stash. Here are the modifications, maybe you'll be interested.

Cheers,
--
José A. Romero L.
escherdragon@gmail.com
"We who cut mere stones must always be envisioning cathedrals."
(Quarry worker's creed)