discovery: add Consul SD support (#18)

go.mod

@@ -6,6 +6,7 @@ require (
 	github.com/gagliardetto/solana-go v1.4.0
 	github.com/gin-contrib/zap v0.0.2
 	github.com/gin-gonic/gin v1.7.7
+	github.com/hashicorp/consul/api v1.12.0
 	github.com/hashicorp/go-memdb v1.3.3
 	github.com/minio/minio-go/v7 v7.0.24
 	github.com/prometheus/client_golang v1.12.1
@@ -26,6 +27,7 @@ require (
 	filippo.io/edwards25519 v1.0.0-rc.1 // indirect
 	github.com/VividCortex/ewma v1.2.0 // indirect
 	github.com/acarl005/stripansi v0.0.0-20180116102854-5a71ef0e047d // indirect
+	github.com/armon/go-metrics v0.0.0-20180917152333-f0300d1749da // indirect
 	github.com/aybabtme/rgbterm v0.0.0-20170906152045-cc83f3b3ce59 // indirect
 	github.com/benbjohnson/clock v1.1.0 // indirect
 	github.com/beorn7/perks v1.0.1 // indirect
@@ -44,8 +46,12 @@ require (
 	github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da // indirect
 	github.com/golang/protobuf v1.5.2 // indirect
 	github.com/google/uuid v1.1.2 // indirect
+	github.com/hashicorp/go-cleanhttp v0.5.1 // indirect
+	github.com/hashicorp/go-hclog v0.12.0 // indirect
 	github.com/hashicorp/go-immutable-radix v1.3.0 // indirect
+	github.com/hashicorp/go-rootcerts v1.0.2 // indirect
 	github.com/hashicorp/golang-lru v0.5.4 // indirect
+	github.com/hashicorp/serf v0.9.6 // indirect
 	github.com/inconshreveable/mousetrap v1.0.0 // indirect
 	github.com/json-iterator/go v1.1.12 // indirect
 	github.com/klauspost/compress v1.15.1 // indirect
@@ -61,6 +67,7 @@ require (
 	github.com/minio/sha256-simd v0.1.1 // indirect
 	github.com/mitchellh/go-homedir v1.1.0 // indirect
 	github.com/mitchellh/go-testing-interface v1.14.1 // indirect
+	github.com/mitchellh/mapstructure v1.1.2 // indirect
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.2 // indirect
 	github.com/mostynb/zstdpool-freelist v0.0.0-20201229113212-927304c0c3b1 // indirect