all: improve the method of import for internal packages

1. Change directory structure and Makefile to let GOPATH=`pwd`, so wherever the project directory is, just use make to build.

src/frp/utils/pcrypto/pcrypto_test.go

@@ -0,0 +1,47 @@
+package pcrypto
+
+import (
+	"crypto/aes"
+	"fmt"
+	"testing"
+)
+
+func TestEncrypto(t *testing.T) {
+	pp := new(Pcrypto)
+	pp.Init([]byte("Hana"))
+	res, err := pp.Encrypto([]byte("Just One Test!"))
+	if err != nil {
+		t.Error(err)
+	}
+
+	fmt.Printf("[%x]\n", res)
+}
+
+func TestDecrypto(t *testing.T) {
+	pp := new(Pcrypto)
+	pp.Init([]byte("Hana"))
+	res, err := pp.Encrypto([]byte("Just One Test!"))
+	if err != nil {
+		t.Error(err)
+	}
+
+	res, err = pp.Decrypto(res)
+	if err != nil {
+		t.Error(err)
+	}
+
+	fmt.Printf("[%s]\n", string(res))
+}
+
+func TestPKCS7Padding(t *testing.T) {
+	ltt := []byte("Test_PKCS7Padding")
+	ltt = PKCS7Padding(ltt, aes.BlockSize)
+	fmt.Printf("[%x]\n", (ltt))
+}
+
+func TestPKCS7UnPadding(t *testing.T) {
+	ltt := []byte("Test_PKCS7Padding")
+	ltt = PKCS7Padding(ltt, aes.BlockSize)
+	ltt = PKCS7UnPadding(ltt)
+	fmt.Printf("[%x]\n", ltt)
+}