We use the `id` of the upload to calculate a `depth` partition in the
filename. This test would fail if your database had a higher seed
because the depth it was looking for was hard coded to 1.
The solution was to not save the records (which is faster anyway) and
specify the `id` of the upload to make the hash deterministic.
This updates tests to use latest rails 5 practice
and updates ALL dependencies that could be updated
Performance testing shows that performance has not regressed
if anything it is marginally faster now.