fix golint issues in rest (#529)

rest/httpx/vars.go

@@ -1,19 +1,31 @@
 package httpx
 
 const (
+	// ApplicationJson means application/json.
 	ApplicationJson = "application/json"
+	// ContentEncoding means Content-Encoding.
 	ContentEncoding = "Content-Encoding"
+	// ContentSecurity means X-Content-Security.
 	ContentSecurity = "X-Content-Security"
-	ContentType     = "Content-Type"
-	KeyField        = "key"
-	SecretField     = "secret"
-	TypeField       = "type"
-	CryptionType    = 1
+	// ContentType means Content-Type.
+	ContentType = "Content-Type"
+	// KeyField means key.
+	KeyField = "key"
+	// SecretField means secret.
+	SecretField = "secret"
+	// TypeField means type.
+	TypeField = "type"
+	// CryptionType means cryption.
+	CryptionType = 1
 )
 
 const (
+	// CodeSignaturePass means signature verification passed.
 	CodeSignaturePass = iota
+	// CodeSignatureInvalidHeader means invalid header in signature.
 	CodeSignatureInvalidHeader
+	// CodeSignatureWrongTime means wrong timestamp in signature.
 	CodeSignatureWrongTime
+	// CodeSignatureInvalidToken means invalid token in signature.
 	CodeSignatureInvalidToken
 )