moving from Godeps to Go 1.5 vendoring

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

@@ -0,0 +1,43 @@
+package jwt
+
+import (
+	"errors"
+)
+
+// Error constants
+var (
+	ErrInvalidKey       = errors.New("key is invalid or of invalid type")
+	ErrHashUnavailable  = errors.New("the requested hash function is unavailable")
+	ErrNoTokenInRequest = errors.New("no token present in request")
+)
+
+// The errors that might occur when parsing and validating a token
+const (
+	ValidationErrorMalformed        uint32 = 1 << iota // Token is malformed
+	ValidationErrorUnverifiable                        // Token could not be verified because of signing problems
+	ValidationErrorSignatureInvalid                    // Signature validation failed
+	ValidationErrorExpired                             // Exp validation failed
+	ValidationErrorNotValidYet                         // NBF validation failed
+)
+
+// The error from Parse if token is not valid
+type ValidationError struct {
+	err    string
+	Errors uint32 // bitfield.  see ValidationError... constants
+}
+
+// Validation error is an error type
+func (e ValidationError) Error() string {
+	if e.err == "" {
+		return "token is invalid"
+	}
+	return e.err
+}
+
+// No errors
+func (e *ValidationError) valid() bool {
+	if e.Errors > 0 {
+		return false
+	}
+	return true
+}