Add a new job

Property definitions

github $ Loader :: add_job
	# Add a new job
	fun add_job(repo_slug: String): LoaderJob do
		var repo = config.wallet.api.get_repo(repo_slug)
		assert repo != null else
			error "Repository `{repo_slug}` not found"
		end
		repos.save repo
		var job = new LoaderJob(repo, config.start_from_issue)
		jobs.save job
		return job
	end
lib/github/loader.nit:274,2--284,4