For the 1.8.0 release, let's do the following for each site config:

• Verify OSes
• Remove old/unused compilers
• Check compiler versions
• Check external package paths/versions
• Create a test environment, concretize, and install a few packages

Site list:

• acorn (@AlexanderRichert-NOAA)
• atlantis (@climbfuji)
• blueback (@climbfuji)
• aws-pcluster currently not supported
• casper - move to tier2 (@climbfuji)
• derecho
• discover-scu16 no longer supported
• discover-scu17
• emc-rhel currently not supported
• frontera no longer supported
• gaea-c5
• gaea-c6
• hera
• hercules
• jet no longer supported
• linux.default
• macos.default
• narwhal (@climbfuji)
• nautilus (@climbfuji)
• noaa-aws
• noaa-azure
• noaa-gcloud
• orion
• s4