Add integration with new UK TRUD release distribution API.

[wardle]

Need to have a modular system to make it much easier to download regional SNOMED distributions. In the UK, this is via TRUD, but different in other regions. Would be very helpful to make it easy to automate this process and keep any single service up-to-date, or instead have a bootstrapping system to create a new service based on the latest distribution files.

[wardle]

I've now build a way to integrate with the UK TRUD API. See https://github.com/wardle/trud - need to integrate this and make it easy to bootstrap, irrespective of where you are in the World, while ensuring the user is working under the license conditions of SNOMED International.