Some Tutorial and Docker-related updates for v6

[mkavulich]

• Updating Dockerfile for latest release
  • Adding myself as a maintainer
  • restoring the old NCEPLIBS build script as a stopgap before we upgrade to newest hpc-stack or spack
  • Call new data retrieval script
  • Add environment variables that are needed for running so user doesn't need to set them manually
• Updating run script
  • Remove extra debug layer to avoid having normal messages show up as warnings
  • Update "copy_outdir" function to be able to work from any directory, not just run directory (this prevents errors in docker container)

Tests run: Used this branch (modified slightly to avoid chicken-egg problem) to build dockerfile and run tutorial case successfully with resulting docker image (can be downloaded from Dockerhub: docker pull dtcenter/ccpp-scm:v6.0.0-beta)