SEBA-902 single-olt tests;
Pin protoc-gen-go to 1.3.2 to resolve compatibility issue;
Run go mod tidy / go mod vendor on importer;
Add Go Module support to demotest

Change-Id: Ifde824fc9a6317b0adc1e12bea54ee1f9b788906
diff --git a/demo_test/vendor/gopkg.in/jcmturner/gokrb5.v7/types/Cryptosystem.go b/demo_test/vendor/gopkg.in/jcmturner/gokrb5.v7/types/Cryptosystem.go
new file mode 100644
index 0000000..7e8b4ab
--- /dev/null
+++ b/demo_test/vendor/gopkg.in/jcmturner/gokrb5.v7/types/Cryptosystem.go
@@ -0,0 +1,55 @@
+package types
+
+import (
+	"github.com/jcmturner/gofork/encoding/asn1"
+)
+
+// Reference: https://www.ietf.org/rfc/rfc4120.txt
+// Section: 5.2.9
+
+// EncryptedData implements RFC 4120 type: https://tools.ietf.org/html/rfc4120#section-5.2.9
+type EncryptedData struct {
+	EType  int32  `asn1:"explicit,tag:0"`
+	KVNO   int    `asn1:"explicit,optional,tag:1"`
+	Cipher []byte `asn1:"explicit,tag:2"`
+}
+
+// EncryptionKey implements RFC 4120 type: https://tools.ietf.org/html/rfc4120#section-5.2.9
+// AKA KeyBlock
+type EncryptionKey struct {
+	KeyType  int32  `asn1:"explicit,tag:0"`
+	KeyValue []byte `asn1:"explicit,tag:1"`
+}
+
+// Checksum implements RFC 4120 type: https://tools.ietf.org/html/rfc4120#section-5.2.9
+type Checksum struct {
+	CksumType int32  `asn1:"explicit,tag:0"`
+	Checksum  []byte `asn1:"explicit,tag:1"`
+}
+
+// Unmarshal bytes into the EncryptedData.
+func (a *EncryptedData) Unmarshal(b []byte) error {
+	_, err := asn1.Unmarshal(b, a)
+	return err
+}
+
+// Marshal the EncryptedData.
+func (a *EncryptedData) Marshal() ([]byte, error) {
+	edb, err := asn1.Marshal(*a)
+	if err != nil {
+		return edb, err
+	}
+	return edb, nil
+}
+
+// Unmarshal bytes into the EncryptionKey.
+func (a *EncryptionKey) Unmarshal(b []byte) error {
+	_, err := asn1.Unmarshal(b, a)
+	return err
+}
+
+// Unmarshal bytes into the Checksum.
+func (a *Checksum) Unmarshal(b []byte) error {
+	_, err := asn1.Unmarshal(b, a)
+	return err
+}