3.0.1 0.47.x compatibility

Changes to support the 0.47.x chain upgrade.

What's Changed

• 2.2.0 0.50.x compatibility by @geoffmunn in #13
• Version bump and README updated by @geoffmunn in #14
• 2.2.0 0.50.x compatibility by @geoffmunn in #15

Full Changelog: v2.1.4...v3.0.1