Fixed linter's warnings. Add docstrings

aws.go

@@ -14,7 +14,7 @@ const (
 	CheckTypeTCP CheckType = iota
 	// CheckTypeHTTP is HTTP type of check
 	CheckTypeHTTP
-	// CheckTypeHTTP is HTTPS type of check
+	// CheckTypeHTTPS is HTTPS type of check
 	CheckTypeHTTPS
 )
 

request.go

@@ -6,19 +6,25 @@ import (
 	"time"
 )
 
+// RequestType describes a type for a request type
 type RequestType int
 
 const (
+	// RequestTypeHTTP is HTTP type of request
 	RequestTypeHTTP RequestType = iota
+	// RequestTypeTCP is TCP type of request
 	RequestTypeTCP
 )
 
+// Requester is an interface to do a network request
 type Requester interface {
 	Do(ua, url string, reqType RequestType) (time.Duration, error)
 }
 
+// AWSRequest implements Requester interface
 type AWSRequest struct{}
 
+// DoHTTP does HTTP request for a URL by User-Agent (ua)
 func (r *AWSRequest) DoHTTP(ua, url string) (time.Duration, error) {
 	client := &http.Client{}
 
@@ -40,7 +46,8 @@ func (r *AWSRequest) DoHTTP(ua, url string) (time.Duration, error) {
 	return latency, nil
 }
 
-func (r *AWSRequest) DoTCP(ua, addr string) (time.Duration, error) {
+// DoTCP does TCP request to the Addr
+func (r *AWSRequest) DoTCP(_, addr string) (time.Duration, error) {
 	d := net.Dialer{}
 
 	start := time.Now()
@@ -54,6 +61,7 @@ func (r *AWSRequest) DoTCP(ua, addr string) (time.Duration, error) {
 	return l, nil
 }
 
+// Do does a request. Type of request depends on reqType
 func (r *AWSRequest) Do(ua, url string, reqType RequestType) (time.Duration, error) {
 	if reqType == RequestTypeHTTP {
 		return r.DoHTTP(ua, url)

utils.go

@@ -13,12 +13,14 @@ import (
 )
 
 var (
+	// Version describes application version
 	Version   = "1.0.0"
 	github    = "https://github.com/ekalinin/awsping"
 	useragent = fmt.Sprintf("AwsPing/%s (+%s)", Version, github)
 )
 
 const (
+	// ShowOnlyRegions describes a type of output when only region's name and code printed out
 	ShowOnlyRegions = -1
 )
 
@@ -45,6 +47,7 @@ type LatencyOutput struct {
 	w       io.Writer
 }
 
+// NewOutput creates a new LatencyOutput instance
 func NewOutput(level, repeats int) *LatencyOutput {
 	return &LatencyOutput{
 		Level:   level,