Fixed lint issues, set Go version to 1.16.4

Dockerfile

@@ -1,4 +1,4 @@
-FROM golang:1.16 AS build_base
+FROM golang:1.16.4 AS build_base
 
 ## Usage:
 ## docker build . -t gokapi

build/Dockerfile

@@ -1,4 +1,4 @@
-FROM golang:1.16
+FROM golang:1.16.4
 
 ## To compile:
 ## cd Gokapi/build/

internal/models/Api.go

@@ -6,4 +6,4 @@ type ApiKey struct {
 	FriendlyName   string `json:"FriendlyName"`
 	LastUsed       int64  `json:"LastUsed"`
 	LastUsedString string `json:"LastUsedString"`
-}
+}

internal/models/FileUpload.go

@@ -1,9 +1,10 @@
 package models
 
+// UploadRequest is used to set an upload request
 type UploadRequest struct {
 	AllowedDownloads int
 	Expiry           int
-	ExpiryTimestamp int64
+	ExpiryTimestamp  int64
 	Password         string
 	ExternalUrl      string
 }

internal/test/testconfiguration/TestConfiguration_test.go

@@ -31,4 +31,4 @@ func TestSetUpgradeConfigFile(t *testing.T) {
 	WriteUpgradeConfigFile()
 	test.IsEqualBool(t, helper.FileExists(configFile), true)
 	TestDelete(t)
-}
+}

internal/webserver/api/Api.go

@@ -38,6 +38,7 @@ func Process(w http.ResponseWriter, r *http.Request) {
 	}
 }
 
+// DeleteKey deletes the selected API key
 func DeleteKey(id string) bool {
 	if !isValidKey(id, false) {
 		return false
@@ -48,6 +49,7 @@ func DeleteKey(id string) bool {
 	return true
 }
 
+// NewKey generates a new API key
 func NewKey() string {
 	settings := configuration.GetServerSettings()
 	newKey := models.ApiKey{

internal/webserver/fileupload/FileUpload.go

@@ -11,6 +11,7 @@ import (
 	"time"
 )
 
+// Process processes a file upload request
 func Process(w http.ResponseWriter, r *http.Request, isWeb bool) error {
 	err := r.ParseMultipartForm(20 * 1024 * 1024)
 	if err != nil {