Switch to github.com/golang/dep for vendoring

Signed-off-by: Mrunal Patel <mrunalp@gmail.com>

vendor/github.com/opencontainers/image-spec/schema/error.go

@@ -0,0 +1,44 @@
+// Copyright 2016 The Linux Foundation
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package schema
+
+import (
+	"encoding/json"
+	"io"
+
+	"go4.org/errorutil"
+)
+
+// A SyntaxError is a description of a JSON syntax error
+// including line, column and offset in the JSON file.
+type SyntaxError struct {
+	msg       string
+	Line, Col int
+	Offset    int64
+}
+
+func (e *SyntaxError) Error() string { return e.msg }
+
+// WrapSyntaxError checks whether the given error is a *json.SyntaxError
+// and converts it into a *schema.SyntaxError containing line/col information using the given reader.
+// If the given error is not a *json.SyntaxError it is returned unchanged.
+func WrapSyntaxError(r io.Reader, err error) error {
+	if serr, ok := err.(*json.SyntaxError); ok {
+		line, col, _ := errorutil.HighlightBytePosition(r, serr.Offset)
+		return &SyntaxError{serr.Error(), line, col, serr.Offset}
+	}
+
+	return err
+}