Blitline::Job not saving application_id in initializer

[Diasporism]

It looks like the application_id parameter of the initialize method in Blitline::Job is being thrown out instead of saved on the instance. While an easy workaround is to set it after the fact, it would be nice to just be able to pass it into the initializer at instantiation.

I'd be happy to put in a PR and link it back to this issue if you'd like.