Investigate the feasibility of snapshots #123
Description
Snapshots are similar to views in the sense that they have a specification to piece together a graph representation of multiple related CBDs.
Unlike views, as the underlying CBD data is updated they do not regenerate. They are a point in time snapshot of the data.
Snapshots are created on-demand by calling a method in the tripod API to generate them.
Snapshots do not overwrite - the date they were generated is part of their key, so multiple copies can be kept over time.
When reading snapshots, the default is that the last generated snapshot is returned.