Add update method

[ryanteck]

Add update method

[ryanteck]

Ticket Review 11/05/2019 - This will still be implemented at a significantly later point. I don't expect to do many releases after all other feature requests are completed.

[ryanteck]

Targeting for November the 30th Release.

The plan is to move the lora packet forwarder, libraries and controller to Apt by November in time for Standalone Gateway Testing.

For the next two releases most changes will require the entire SD Card updating. However by November it is hoped that we'll move to our own Apt repository or such.

[ryanteck]

Ok so the best way we've thought and done for this is:

The host OS is Yocto or Alpine Linux.

The main bits of software are instead all stored in docker containers allowing easier distributions of upgrades of software even to the point of where if an entire re-write is required it should be a seemlessish update.

[ryanteck]

This will be done in the next image.