diff --git a/vendor/github.com/dgrijalva/jwt-go/claims.go b/vendor/github.com/dgrijalva/jwt-go/claims.go
new file mode 100644
index 0000000..f0228f0
--- /dev/null
+++ b/vendor/github.com/dgrijalva/jwt-go/claims.go
@@ -0,0 +1,134 @@
+package jwt
+
+import (
+	"crypto/subtle"
+	"fmt"
+	"time"
+)
+
+// For a type to be a Claims object, it must just have a Valid method that determines
+// if the token is invalid for any supported reason
+type Claims interface {
+	Valid() error
+}
+
+// Structured version of Claims Section, as referenced at
+// https://tools.ietf.org/html/rfc7519#section-4.1
+// See examples for how to use this with your own claim types
+type StandardClaims struct {
+	Audience  string `json:"aud,omitempty"`
+	ExpiresAt int64  `json:"exp,omitempty"`
+	Id        string `json:"jti,omitempty"`
+	IssuedAt  int64  `json:"iat,omitempty"`
+	Issuer    string `json:"iss,omitempty"`
+	NotBefore int64  `json:"nbf,omitempty"`
+	Subject   string `json:"sub,omitempty"`
+}
+
+// Validates time based claims "exp, iat, nbf".
+// There is no accounting for clock skew.
+// As well, if any of the above claims are not in the token, it will still
+// be considered a valid claim.
+func (c StandardClaims) Valid() error {
+	vErr := new(ValidationError)
+	now := TimeFunc().Unix()
+
+	// The claims below are optional, by default, so if they are set to the
+	// default value in Go, let's not fail the verification for them.
+	if c.VerifyExpiresAt(now, false) == false {
+		delta := time.Unix(now, 0).Sub(time.Unix(c.ExpiresAt, 0))
+		vErr.Inner = fmt.Errorf("token is expired by %v", delta)
+		vErr.Errors |= ValidationErrorExpired
+	}
+
+	if c.VerifyIssuedAt(now, false) == false {
+		vErr.Inner = fmt.Errorf("Token used before issued")
+		vErr.Errors |= ValidationErrorIssuedAt
+	}
+
+	if c.VerifyNotBefore(now, false) == false {
+		vErr.Inner = fmt.Errorf("token is not valid yet")
+		vErr.Errors |= ValidationErrorNotValidYet
+	}
+
+	if vErr.valid() {
+		return nil
+	}
+
+	return vErr
+}
+
+// Compares the aud claim against cmp.
+// If required is false, this method will return true if the value matches or is unset
+func (c *StandardClaims) VerifyAudience(cmp string, req bool) bool {
+	return verifyAud(c.Audience, cmp, req)
+}
+
+// Compares the exp claim against cmp.
+// If required is false, this method will return true if the value matches or is unset
+func (c *StandardClaims) VerifyExpiresAt(cmp int64, req bool) bool {
+	return verifyExp(c.ExpiresAt, cmp, req)
+}
+
+// Compares the iat claim against cmp.
+// If required is false, this method will return true if the value matches or is unset
+func (c *StandardClaims) VerifyIssuedAt(cmp int64, req bool) bool {
+	return verifyIat(c.IssuedAt, cmp, req)
+}
+
+// Compares the iss claim against cmp.
+// If required is false, this method will return true if the value matches or is unset
+func (c *StandardClaims) VerifyIssuer(cmp string, req bool) bool {
+	return verifyIss(c.Issuer, cmp, req)
+}
+
+// Compares the nbf claim against cmp.
+// If required is false, this method will return true if the value matches or is unset
+func (c *StandardClaims) VerifyNotBefore(cmp int64, req bool) bool {
+	return verifyNbf(c.NotBefore, cmp, req)
+}
+
+// ----- helpers
+
+func verifyAud(aud string, cmp string, required bool) bool {
+	if aud == "" {
+		return !required
+	}
+	if subtle.ConstantTimeCompare([]byte(aud), []byte(cmp)) != 0 {
+		return true
+	} else {
+		return false
+	}
+}
+
+func verifyExp(exp int64, now int64, required bool) bool {
+	if exp == 0 {
+		return !required
+	}
+	return now <= exp
+}
+
+func verifyIat(iat int64, now int64, required bool) bool {
+	if iat == 0 {
+		return !required
+	}
+	return now >= iat
+}
+
+func verifyIss(iss string, cmp string, required bool) bool {
+	if iss == "" {
+		return !required
+	}
+	if subtle.ConstantTimeCompare([]byte(iss), []byte(cmp)) != 0 {
+		return true
+	} else {
+		return false
+	}
+}
+
+func verifyNbf(nbf int64, now int64, required bool) bool {
+	if nbf == 0 {
+		return !required
+	}
+	return now >= nbf
+}