diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/errors.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/errors.go
new file mode 100644
index 0000000..a360807
--- /dev/null
+++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/runtime/errors.go
@@ -0,0 +1,146 @@
+package runtime
+
+import (
+	"context"
+	"io"
+	"net/http"
+
+	"github.com/golang/protobuf/proto"
+	"github.com/golang/protobuf/ptypes/any"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/grpclog"
+	"google.golang.org/grpc/status"
+)
+
+// HTTPStatusFromCode converts a gRPC error code into the corresponding HTTP response status.
+// See: https://github.com/googleapis/googleapis/blob/master/google/rpc/code.proto
+func HTTPStatusFromCode(code codes.Code) int {
+	switch code {
+	case codes.OK:
+		return http.StatusOK
+	case codes.Canceled:
+		return http.StatusRequestTimeout
+	case codes.Unknown:
+		return http.StatusInternalServerError
+	case codes.InvalidArgument:
+		return http.StatusBadRequest
+	case codes.DeadlineExceeded:
+		return http.StatusGatewayTimeout
+	case codes.NotFound:
+		return http.StatusNotFound
+	case codes.AlreadyExists:
+		return http.StatusConflict
+	case codes.PermissionDenied:
+		return http.StatusForbidden
+	case codes.Unauthenticated:
+		return http.StatusUnauthorized
+	case codes.ResourceExhausted:
+		return http.StatusTooManyRequests
+	case codes.FailedPrecondition:
+		// Note, this deliberately doesn't translate to the similarly named '412 Precondition Failed' HTTP response status.
+		return http.StatusBadRequest
+	case codes.Aborted:
+		return http.StatusConflict
+	case codes.OutOfRange:
+		return http.StatusBadRequest
+	case codes.Unimplemented:
+		return http.StatusNotImplemented
+	case codes.Internal:
+		return http.StatusInternalServerError
+	case codes.Unavailable:
+		return http.StatusServiceUnavailable
+	case codes.DataLoss:
+		return http.StatusInternalServerError
+	}
+
+	grpclog.Infof("Unknown gRPC error code: %v", code)
+	return http.StatusInternalServerError
+}
+
+var (
+	// HTTPError replies to the request with the error.
+	// You can set a custom function to this variable to customize error format.
+	HTTPError = DefaultHTTPError
+	// OtherErrorHandler handles the following error used by the gateway: StatusMethodNotAllowed StatusNotFound and StatusBadRequest
+	OtherErrorHandler = DefaultOtherErrorHandler
+)
+
+type errorBody struct {
+	Error string `protobuf:"bytes,100,name=error" json:"error"`
+	// This is to make the error more compatible with users that expect errors to be Status objects:
+	// https://github.com/grpc/grpc/blob/master/src/proto/grpc/status/status.proto
+	// It should be the exact same message as the Error field.
+	Code    int32      `protobuf:"varint,1,name=code" json:"code"`
+	Message string     `protobuf:"bytes,2,name=message" json:"message"`
+	Details []*any.Any `protobuf:"bytes,3,rep,name=details" json:"details,omitempty"`
+}
+
+// Make this also conform to proto.Message for builtin JSONPb Marshaler
+func (e *errorBody) Reset()         { *e = errorBody{} }
+func (e *errorBody) String() string { return proto.CompactTextString(e) }
+func (*errorBody) ProtoMessage()    {}
+
+// DefaultHTTPError is the default implementation of HTTPError.
+// If "err" is an error from gRPC system, the function replies with the status code mapped by HTTPStatusFromCode.
+// If otherwise, it replies with http.StatusInternalServerError.
+//
+// The response body returned by this function is a JSON object,
+// which contains a member whose key is "error" and whose value is err.Error().
+func DefaultHTTPError(ctx context.Context, mux *ServeMux, marshaler Marshaler, w http.ResponseWriter, _ *http.Request, err error) {
+	const fallback = `{"error": "failed to marshal error message"}`
+
+	s, ok := status.FromError(err)
+	if !ok {
+		s = status.New(codes.Unknown, err.Error())
+	}
+
+	w.Header().Del("Trailer")
+
+	contentType := marshaler.ContentType()
+	// Check marshaler on run time in order to keep backwards compatability
+	// An interface param needs to be added to the ContentType() function on
+	// the Marshal interface to be able to remove this check
+	if httpBodyMarshaler, ok := marshaler.(*HTTPBodyMarshaler); ok {
+		pb := s.Proto()
+		contentType = httpBodyMarshaler.ContentTypeFromMessage(pb)
+	}
+	w.Header().Set("Content-Type", contentType)
+
+	body := &errorBody{
+		Error:   s.Message(),
+		Message: s.Message(),
+		Code:    int32(s.Code()),
+		Details: s.Proto().GetDetails(),
+	}
+
+	buf, merr := marshaler.Marshal(body)
+	if merr != nil {
+		grpclog.Infof("Failed to marshal error message %q: %v", body, merr)
+		w.WriteHeader(http.StatusInternalServerError)
+		if _, err := io.WriteString(w, fallback); err != nil {
+			grpclog.Infof("Failed to write response: %v", err)
+		}
+		return
+	}
+
+	md, ok := ServerMetadataFromContext(ctx)
+	if !ok {
+		grpclog.Infof("Failed to extract ServerMetadata from context")
+	}
+
+	handleForwardResponseServerMetadata(w, mux, md)
+	handleForwardResponseTrailerHeader(w, md)
+	st := HTTPStatusFromCode(s.Code())
+	w.WriteHeader(st)
+	if _, err := w.Write(buf); err != nil {
+		grpclog.Infof("Failed to write response: %v", err)
+	}
+
+	handleForwardResponseTrailer(w, md)
+}
+
+// DefaultOtherErrorHandler is the default implementation of OtherErrorHandler.
+// It simply writes a string representation of the given error into "w".
+func DefaultOtherErrorHandler(w http.ResponseWriter, _ *http.Request, msg string, code int) {
+	http.Error(w, msg, code)
+}