Upgrade ava

• upgrade ava to patch vulnerabilities 330a80b
• Update README.md 17f2c9e
• Update README.md f922dbc
• Update README.md ca934a2
• Update README.md 35f4afa

v2.0.0...v2.0.1

Version 2

• Merge pull request #2 from s-taylor/version-2 852b55b
• rework completely to use new Set approach 16aa776
• Update README.md a4fa25c

v1.0.0...v2.0.0