A Number of Minor Changes

Changes include:

Rename ds_dev_utils/docker/images -> ds_dev_utils/docker/image
Moving the dockerfile out of ds_dev_utils/docker/image
Adds to the EscrowAPI descriptions to whether api endpoints should be called WITHIN or OUTSIDE a function
Updates gatekeeper description to say it also runs functions
The docker image is created only once: when the gatekeeper starts up.
No more duplicate files within ds_dev_utils/docker/image

TheDataStation / datastation-escrow