Async requests and a client update

These are BREAKING CHANGES. Version is bumped to 1.0.

Application:
* New endpoint /bootstrap/query/:id (HEAD and GET)
* Old endpoint /bootstrap/:ip redirects (303) to the query endpoint

Reponse codes for /bootstrap/query/:id :
* 202 - processing
* 201 - done and successful
* 550 - done and unsuccessful

Client:
* start_bootstrap returns a bootstrap object
* bootstrap.status [:processing, :success, :failed]
* bootstrap.log returns the output of the knife run (or the output so far if the knife run hasn't finished)