Chore: badges, local build

Makefile

@@ -1,6 +1,8 @@
+GO_VERSION:=0.16
+
 .PHONY: build
 build:
-	goreleaser --snapshot --rm-dist
+	goreleaser r --snapshot --rm-dist
 
 .PHONY: test
 test:
@@ -9,5 +11,5 @@ test:
 		--rm \
 		-v $(CURDIR):/src/github.com/Luzilla/dnsbl_exporter \
 		-w /src/github.com/Luzilla/dnsbl_exporter \
-		golang:1.16 \
+		golang:$(GO_VERSION) \
 		sh -c "go mod download && go test ./..."

README.md

@@ -1,6 +1,6 @@
 # dnsbl-exporter
 
-[![CircleCI](https://circleci.com/gh/Luzilla/dnsbl_exporter.svg?style=svg)](https://circleci.com/gh/Luzilla/dnsbl_exporter) [![pr](https://github.com/Luzilla/dnsbl_exporter/actions/workflows/pr.yml/badge.svg)](https://github.com/Luzilla/dnsbl_exporter/actions/workflows/pr.yml) [![Maintainability](https://api.codeclimate.com/v1/badges/31b95e6c679f60e30bea/maintainability)](https://codeclimate.com/github/Luzilla/dnsbl_exporter/maintainability)
+[![pr](https://github.com/Luzilla/dnsbl_exporter/actions/workflows/pr.yml/badge.svg)](https://github.com/Luzilla/dnsbl_exporter/actions/workflows/pr.yml) [![Maintainability](https://api.codeclimate.com/v1/badges/31b95e6c679f60e30bea/maintainability)](https://codeclimate.com/github/Luzilla/dnsbl_exporter/maintainability) [![Go Report Card](https://goreportcard.com/badge/github.com/Luzilla/dnsbl_exporter)](https://goreportcard.com/report/github.com/Luzilla/dnsbl_exporter)
 
 This is a server which checks the configured hosts against various DNSBL (sometimes refered to as RBLs).