Release 9.0.0-0

• chore: adds README updates for a beta version release (3e93a31)
• chore: adds initial polyfill detector (cb2ec2b)
• chore: adds initial browserlist checks to es-check (390b029)
• chore: adds better support for ignoreFile (b84a98d)
• chore: improves logging + option validation (5fd5fea)
• chore: improve parseIgnoreList function (4f6665c)
• feat: adds whitelist + more tests (329a938)
• chore: adds more .escheckrc support (397a933)
• chore: bumps node version (7918ebc)
• Update dependencies (ca24f21)