Update PostgREST to 6.0.1

PostgREST 6.x has some differences that needed troubleshooting to implement correctly via the docker build. Changes to the pg_listen code with more robust cache reloading fixes the issues.

NHDPlus in WATERS March 2019 Update

The new release includes the March 2019 NHDPlus in WATERS updates
See https://www.epa.gov/waterdata/nhdplus-waters
Time of travel navigation and revised WBD allocation remains offline at the present.

LRS code schema added

The dz_lrs schema (https://github.com/pauldzy/pg_dz_lrs) is required for the catchment splitting functionality of watershed delineation. It was overlooked in the first couple of releases.

PostgREST Dockerhub

The length of time and resources needed to compile an altered PostgREST was onerous. Moving this process into dockerhub makes the entire process far speedier.

Working Alpha 0.1.0 Release

Tested on Windows 10 and Ubuntu