v0.0.13

• upd: replace deprecated ioutil methods
• upd: go1.16
• fix: lint issues
• upd: build/lint configs
• upd: dependencies (cgm, golangci-lint)
• upd: use metric.Name() for check type
• upd: remove ':' between plugin and instance id in check display name
• upd: only use default check if plugin AND instance are "defaults"
• add: defaultInstanceID support

Docker images

• docker pull circonus/circonus-unified-agent:latest
• docker pull circonus/circonus-unified-agent:v0.0.13