Amalgamate v0.1.39

• Remove old recovery.
• Now able to reopen an amalgamator.
• Refactor conflict detection, document logic.
• Shift amalgamated write-ahead logs.
• Rotate and shutdown.
• Skip call to flush and it is now performant.
• Shutting down correctly.
• Filter stages by snapshot on read.
• Each stage had only one group.
• Adapt for use of a write-ahead log.
• Upgrade dilute to 2.0.0-alpha.7.
• Upgrade skip to 0.2.14.
• Upgrade interrupt to 11.0.0-alpha.16.
• Upgrade b-tree to 2.0.0-alpha.72.
• Upgrade homogenize to 2.0.0-alpha.15.
• Upgrade designate to 2.0.0-alpha.15.
• Upgrade splice to 3.0.0-alpha.33.
• Upgrade twiddle to 2.0.0-alpha.8.
• Upgrade whittle to 0.0.1.
• Upgrade reciprocate to 0.0.5.
• Upgrade ascension to 3.0.0-alpha.2.
• Upgrade destructible to 7.0.0-alpha.30.
• Upgrade rescue to 7.0.0-alpha.9.
• Upgrade turnstile to 6.0.0-alpha.43.
• Upgrade magazine to 6.0.0-alpha.5.
• Upgrade riffle to 2.0.0-alpha.47.
• Update LICENSE for 2021.
• Build with Node.js 12, 14 and 15 on CI/CD.
• Replace Prospective with Eject.
• Upgrade b-tree to 2.0.0-alpha.69.
• Upgrade skip to 0.2.12.
• Upgrade homogenize to 2.0.0-alpha.14.
• Upgrade designate to 2.0.0-alpha.14.
• Upgrade splice to 3.0.0-alpha.32.
• Upgrade ascension to 3.0.0-alpha.1.
• Upgrade riffle to 2.0.0-alpha.46.
• Upgrade interrupt to 11.0.0-alpha.14.
• Upgrade destructible to 7.0.0-alpha.26.
• Upgrade rescue to 7.0.0-alpha.8.
• Upgrade reciprocate to 0.0.3.

Closes #208.