4.0.0 release

[adamralph]

• alpha 1 - 3rd Apr
  • MinVer
  • minver-cli
  • https://github.com/adamralph/bullseye
  • https://github.com/adamralph/simple-exec
• RC 1 - 4th May
  • MinVer
  • minver-cli
  • https://github.com/adamralph/bullseye
  • https://github.com/adamralph/simple-exec
• ensure README.md reflects new version
• build tag
• push package
• create next milestone
• close milestone
• update changelog
• tweet, mentioning contributors - _tweet-1525793961151025152