Reactor v17.0.0-alpha.3

• Update to remove depreceation warnings.
• Replace anonymous functions with blocks.
• Update LICENSE for 2021.
• Upgrade destructible to ^7.0.0-alpha.48.
• Build with Node.js 12, 14 and 15 on CI/CD.
• Upgrade fastify to 3.11.0.
• Update .gitignore.
• Upgrade proof to ^9.0.3.
• Upgrade axios to 0.21.1.

Closes #139.

Reactor v17.0.0-alpha.2

• Create Markdown readme with badges. Closes #130.
• Build with Actions, ship coverage to Codecov. Closes #129. Closes #128.
• Upgrade fastify to 2.10.0. Closes #136.
• Pin axios to 0.19.0. Closes #135.
• Tidy .gitignore. Closes #134.

Closes #137.

Reactor v17.0.0-alpha.1

• Upgrade destructible to ^5.2.0-alpha.1. Closes #132.
• Upgrade fastify to 2.9.0. Closes #131.
• Revert test to Proof. Closes #127.

Closes #133.