Updated jwt vendor

Signed-off-by: Derek Collison <derek@nats.io>

vendor/github.com/nats-io/jwt/account_claims.go

@@ -1,8 +1,9 @@
 package jwt
 
 import (
+	"errors"
+
 	"github.com/nats-io/nkeys"
-	"github.com/pkg/errors"
 )
 
 // OperatorLimits are used to limit access by an account

vendor/github.com/nats-io/jwt/header.go

@@ -9,7 +9,7 @@ import (
 
 const (
 	// Version
-	Version = "0.0.1"
+	Version = "0.0.2"
 
 	// TokenTypeJwt is the JWT token type supported JWT tokens
 	// encoded and decoded by this library

vendor/manifest

@@ -5,7 +5,7 @@
 			"importpath": "github.com/nats-io/jwt",
 			"repository": "https://github.com/nats-io/jwt",
 			"vcs": "git",
-			"revision": "c9990f0bf372fd746f55af838ab0b64bbdf8d8ed",
+			"revision": "b4c212c5231ae92718a10abeff5157a837628a1e",
 			"branch": "master",
 			"notests": true
 		},