v1.8.0: 💪🏼 arm64 support for M1 Macs

• ✨ Support for Apple Silicon (arm64) #310
  thanks, @chris-araman!
  • ⚒️ Xcode 12.2 and macOS 10.15.4 required to build
• 🕊 Swift 5.2 #310
  • ⚒️ Xcode 11.4 and macOS 10.15.2 required to build
• 🐛 Specify desired LD_RUNPATH_SEARCH_PATHS at link-time #310
• 🐛 Default PREFIX to /opt/homebrew on Apple Silicon (arm64)
• ⬆️ Commandant (0.18.0) #310
• ⬆️ Nimble (9.0.0) #310
• ⬆️ Quick (3.1.0) #310
• 🎨 Improve mas list command output #278
  thanks, @danielbayley!
• 🐛 Fix alignment of 2nd column of list command output #298
• ✨ Makefile #277