2.7.0

What's Changed

• Bump ruby from 2.6.5-slim-buster to 2.7.0-slim-buster by @dependabot-preview in #38
• Updates for Travis CI by @genebean in #39
• Prometheus custom metrics by @genebean in #40
• Release 2.7.0 by @genebean in #41

Full Changelog: 2.6.2...2.7.0