Update vendor for Azure dependencies

Signed-off-by: Stephen Augustus <saugustus@vmware.com>

vendor/github.com/dgrijalva/jwt-go/hmac.go

@@ -7,6 +7,7 @@ import (
 )
 
 // Implements the HMAC-SHA family of signing methods signing methods
+// Expects key type of []byte for both signing and validation
 type SigningMethodHMAC struct {
 	Name string
 	Hash crypto.Hash
@@ -90,5 +91,5 @@ func (m *SigningMethodHMAC) Sign(signingString string, key interface{}) (string,
 		return EncodeSegment(hasher.Sum(nil)), nil
 	}
 
-	return "", ErrInvalidKey
+	return "", ErrInvalidKeyType
 }