diff --git a/go/vendor/github.com/go-openapi/errors/headers.go b/go/vendor/github.com/go-openapi/errors/headers.go
new file mode 100644
index 0000000..a80ddc9
--- /dev/null
+++ b/go/vendor/github.com/go-openapi/errors/headers.go
@@ -0,0 +1,85 @@
+// Copyright 2015 go-swagger maintainers
+//
+// 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 errors
+
+import (
+	"fmt"
+	"net/http"
+)
+
+// Validation represents a failure of a precondition
+type Validation struct {
+	code    int32
+	Name    string
+	In      string
+	Value   interface{}
+	message string
+	Values  []interface{}
+}
+
+func (e *Validation) Error() string {
+	return e.message
+}
+
+// Code the error code
+func (e *Validation) Code() int32 {
+	return e.code
+}
+
+// ValidateName produces an error message name for an aliased property
+func (e *Validation) ValidateName(name string) *Validation {
+	if e.Name == "" && name != "" {
+		e.Name = name
+		e.message = name + e.message
+	}
+	return e
+}
+
+const (
+	contentTypeFail    = `unsupported media type %q, only %v are allowed`
+	responseFormatFail = `unsupported media type requested, only %v are available`
+)
+
+// InvalidContentType error for an invalid content type
+func InvalidContentType(value string, allowed []string) *Validation {
+	var values []interface{}
+	for _, v := range allowed {
+		values = append(values, v)
+	}
+	return &Validation{
+		code:    http.StatusUnsupportedMediaType,
+		Name:    "Content-Type",
+		In:      "header",
+		Value:   value,
+		Values:  values,
+		message: fmt.Sprintf(contentTypeFail, value, allowed),
+	}
+}
+
+// InvalidResponseFormat error for an unacceptable response format request
+func InvalidResponseFormat(value string, allowed []string) *Validation {
+	var values []interface{}
+	for _, v := range allowed {
+		values = append(values, v)
+	}
+	return &Validation{
+		code:    http.StatusNotAcceptable,
+		Name:    "Accept",
+		In:      "header",
+		Value:   value,
+		Values:  values,
+		message: fmt.Sprintf(responseFormatFail, allowed),
+	}
+}