Configurable Readiness Levels

What's Changed

This release removed the predefined Readiness Levels (with their links to Lightbend) and makes them configurable in sbt instead.

Changes

• Replace bintray badge with maven-central by @mdedetrich in #33
• Make ReadinessLevel's configurable by @mdedetrich in #34

Full Changelog: v1.1.10...v2.0.0