Upgrade prometheus/client_golang module and golang versions to late…

…st (#18)

* Upgrading both "prometheus/client_golang" and golang version to latest releases

* Addressing deprecated "ioutil" use and incorrect format string for "caCertificate" variable

Dockerfile

@@ -1,4 +1,4 @@
-FROM golang:1.17
+FROM golang:1.21
 
 COPY . /go/src/github.com/maxctrl_exporter
 

go.mod

@@ -1,19 +1,19 @@
 module github.com/maxctrl_exporter
 
-go 1.17
+go 1.21
 
 require (
 	github.com/beorn7/perks v1.0.1 // indirect
-	github.com/matttproud/golang_protobuf_extensions v1.0.1 // indirect
-	github.com/prometheus/client_golang v1.11.0
-	github.com/prometheus/client_model v0.2.0 // indirect
-	github.com/prometheus/common v0.31.1 // indirect
-	github.com/prometheus/procfs v0.7.3 // indirect
-	google.golang.org/protobuf v1.27.1 // indirect
+	github.com/matttproud/golang_protobuf_extensions v1.0.4 // indirect
+	github.com/prometheus/client_golang v1.17.0
+	github.com/prometheus/client_model v0.4.1-0.20230718164431-9a2bf3000d16 // indirect
+	github.com/prometheus/common v0.44.0 // indirect
+	github.com/prometheus/procfs v0.11.1 // indirect
+	google.golang.org/protobuf v1.31.0 // indirect
 )
 
 require (
-	github.com/cespare/xxhash/v2 v2.1.1 // indirect
-	github.com/golang/protobuf v1.5.0 // indirect
-	golang.org/x/sys v0.0.0-20210603081109-ebe580a85c40 // indirect
+	github.com/cespare/xxhash/v2 v2.2.0 // indirect
+	github.com/golang/protobuf v1.5.3 // indirect
+	golang.org/x/sys v0.11.0 // indirect
 )