Update Go version to 1.17 (#211)

Author: lucacome

build/Dockerfile

@@ -1,4 +1,4 @@
-FROM golang:1.16 as base
+FROM golang:1.17 as base
 ARG VERSION
 ARG GIT_COMMIT
 ARG DATE

go.mod

@@ -1,9 +1,20 @@
 module github.com/nginxinc/nginx-prometheus-exporter
 
-go 1.16
+go 1.17
 
 require (
 	github.com/nginxinc/nginx-plus-go-client v0.8.0
 	github.com/prometheus/client_golang v1.11.0
 	github.com/prometheus/common v0.30.0
 )
+
+require (
+	github.com/beorn7/perks v1.0.1 // indirect
+	github.com/cespare/xxhash/v2 v2.1.1 // indirect
+	github.com/golang/protobuf v1.4.3 // indirect
+	github.com/matttproud/golang_protobuf_extensions v1.0.1 // indirect
+	github.com/prometheus/client_model v0.2.0 // indirect
+	github.com/prometheus/procfs v0.6.0 // indirect
+	golang.org/x/sys v0.0.0-20210603081109-ebe580a85c40 // indirect
+	google.golang.org/protobuf v1.26.0-rc.1 // indirect
+)