v0.5.3

What's Changed

• Return 503 from proxy when no primary available by @benbjohnson in #373
• Add 'enabled' flag to tracing config by @benbjohnson in #374
• Delay proxy listen until marked ready by @benbjohnson in #378
• Expose lag as prometheus metric by @benbjohnson in #379
• Fix close errors by @benbjohnson in #380
• Proxy health check by @benbjohnson in #381

Full Changelog: v0.5.2...v0.5.3