Move configuration elements to repository

[bryancross]

ATM there's a single config file. This won't scale, because different repositories may have different configuration requires such as default branch, different authentication credentials etc. We should move as many elements of job-template.json to a file in a directory, perhaps .key2pdf in each repository where it's use is desired. The job-template.json file on the server should only include the minimum necessary to bootstrap the server and connect to a repository in order to retrieve the configuration file.