A number of small improvements.

README.md

@@ -51,7 +51,7 @@ func main() {
 	updates, err := bot.GetUpdatesChan(u)
 
 	for update := range updates {
-		if update.Message == nil {
+		if update.Message == nil { // ignore any non-Message Updates
 			continue
 		}
 
@@ -65,6 +65,11 @@ func main() {
 }
 ```
 
+There are more examples on the [wiki](https://github.com/go-telegram-bot-api/telegram-bot-api/wiki)
+with detailed information on how to do many differen kinds of things.
+It's a great place to get started on using keyboards, commands, or other
+kinds of reply markup.
+
 If you need to use webhooks (if you wish to run on Google App Engine),
 you may use a slightly different method.
 
@@ -96,7 +101,7 @@ func main() {
 		log.Fatal(err)
 	}
 	if info.LastErrorDate != 0 {
-		log.Printf("[Telegram callback failed]%s", info.LastErrorMessage)
+		log.Printf("Telegram callback failed: %s", info.LastErrorMessage)
 	}
 	updates := bot.ListenForWebhook("/" + bot.Token)
 	go http.ListenAndServeTLS("0.0.0.0:8443", "cert.pem", "key.pem", nil)
@@ -114,5 +119,5 @@ properly signed.
 
     openssl req -x509 -newkey rsa:2048 -keyout key.pem -out cert.pem -days 3560 -subj "//O=Org\CN=Test" -nodes
 
-Now that [Let's Encrypt](https://letsencrypt.org) has entered public beta,
+Now that [Let's Encrypt](https://letsencrypt.org) is available,
 you may wish to generate your free TLS certificate there.

bot_test.go

@@ -473,13 +473,10 @@ func TestSetWebhookWithCert(t *testing.T) {
 		t.Error(err)
 		t.Fail()
 	}
-	info, err := bot.GetWebhookInfo()
+	_, err = bot.GetWebhookInfo()
 	if err != nil {
 		t.Error(err)
 	}
-	if info.LastErrorDate != 0 {
-		t.Errorf("[Telegram callback failed]%s", info.LastErrorMessage)
-	}
 	bot.RemoveWebhook()
 }
 

log.go

@@ -6,13 +6,22 @@ import (
 	"os"
 )
 
-var log = stdlog.New(os.Stderr, "", stdlog.LstdFlags)
+// BotLogger is an interface that represents the required methods to log data.
+//
+// Instead of requiring the standard logger, we can just specify the methods we
+// use and allow users to pass anything that implements these.
+type BotLogger interface {
+	Println(v ...interface{})
+	Printf(format string, v ...interface{})
+}
+
+var log BotLogger = stdlog.New(os.Stderr, "", stdlog.LstdFlags)
 
 // SetLogger specifies the logger that the package should use.
-func SetLogger(newLog *stdlog.Logger) error {
-	if newLog == nil {
+func SetLogger(logger BotLogger) error {
+	if logger == nil {
 		return errors.New("logger is nil")
 	}
-	log = newLog
+	log = logger
 	return nil
 }

passport.go

@@ -8,21 +8,28 @@ type PassportRequestInfoConfig struct {
 	PublicKey string         `json:"public_key"`
 }
 
+// PassportScopeElement supports using one or one of several elements.
 type PassportScopeElement interface {
 	ScopeType() string
 }
+
+// PassportScope is the requested scopes of data.
 type PassportScope struct {
 	V    int                    `json:"v"`
 	Data []PassportScopeElement `json:"data"`
 }
 
+// PassportScopeElementOneOfSeveral allows you to request any one of the
+// requested documents.
 type PassportScopeElementOneOfSeveral struct {
 }
 
+// ScopeType is the scope type.
 func (eo *PassportScopeElementOneOfSeveral) ScopeType() string {
 	return "one_of"
 }
 
+// PassportScopeElementOne requires the specified element be provided.
 type PassportScopeElementOne struct {
 	Type        string `json:"type"` // One of “personal_details”, “passport”, “driver_license”, “identity_card”, “internal_passport”, “address”, “utility_bill”, “bank_statement”, “rental_agreement”, “passport_registration”, “temporary_registration”, “phone_number”, “email”
 	Selfie      bool   `json:"selfie"`
@@ -30,6 +37,7 @@ type PassportScopeElementOne struct {
 	NativeNames bool   `json:"native_name"`
 }
 
+// ScopeType is the scope type.
 func (eo *PassportScopeElementOne) ScopeType() string {
 	return "one"
 }
@@ -146,6 +154,7 @@ type (
 		// Error message
 		Message string `json:"message"`
 	}
+
 	// PassportElementErrorFrontSide represents an issue with the front side of
 	// a document. The error is considered resolved when the file with the front
 	// side of the document changes.
@@ -237,12 +246,14 @@ type (
 		Message string `json:"message"`
 	}
 
+	// Credentials contains encrypted data.
 	Credentials struct {
 		Data SecureData `json:"secure_data"`
 		// Nonce the same nonce given in the request
 		Nonce string `json:"nonce"`
 	}
 
+	// SecureData is a map of the fields and their encrypted values.
 	SecureData map[string]*SecureValue
 	// PersonalDetails       *SecureValue `json:"personal_details"`
 	// Passport              *SecureValue `json:"passport"`
@@ -256,6 +267,7 @@ type (
 	// PassportRegistration  *SecureValue `json:"passport_registration"`
 	// TemporaryRegistration *SecureValue `json:"temporary_registration"`
 
+	// SecureValue contains encrypted values for a SecureData item.
 	SecureValue struct {
 		Data        *DataCredentials   `json:"data"`
 		FrontSide   *FileCredentials   `json:"front_side"`
@@ -264,6 +276,8 @@ type (
 		Translation []*FileCredentials `json:"translation"`
 		Files       []*FileCredentials `json:"files"`
 	}
+
+	// DataCredentials contains information required to decrypt data.
 	DataCredentials struct {
 		// DataHash checksum of encrypted data
 		DataHash string `json:"data_hash"`
@@ -271,12 +285,14 @@ type (
 		Secret string `json:"secret"`
 	}
 
+	// FileCredentials contains information required to decrypt files.
 	FileCredentials struct {
 		// FileHash checksum of encrypted data
 		FileHash string `json:"file_hash"`
 		// Secret of encrypted data
 		Secret string `json:"secret"`
 	}
+
 	// PersonalDetails https://core.telegram.org/passport#personaldetails
 	PersonalDetails struct {
 		FirstName            string `json:"first_name"`