v0.21.0

• Update avro4s-core to 3.0.8 (#806)
• Update monocle-core to 2.0.2 (#805)
• Update metrics-core to 4.1.4 (#810)
• Fix nearly all the compiler warnings in production code and tests (#809)
• Update pureconfig to 0.12.3 (#811)
• Update cats-effect to 2.1.2 (#812)
• Automatically register muSrcGen as a sourceGenerator (#813)
• Speed up the sbt plugin scripted tests (#814)
• Cross compile code with Scala 2.13.x (#807)
• Fixes sbt Plugin Publish (#818)
• Explicit scala version in Travis Script (#819)
• Update monocle-core to 2.0.4 (#821)
• Remove sbt-org-policies dependency syntax (#822)
• Remove unnecessary publishLocal before running scripted tests (#823)
• Removes Examples from this Repository (#824)
• Update avro4s-core to 3.0.9 (#828)
• Update metrics-core to 4.1.5 (#829)
• Docs refresh (#820)
• Add methods with Resource to GrpcServer and ManagedChannelInterpreter (#830)
• Release 0.21.0 (#831)