Update go.mod and vendor

vendor/github.com/genuinetools/img/AUTHORS

@@ -1,16 +0,0 @@
-# This file lists all individuals having contributed content to the repository.
-# For how it is generated, see `make AUTHORS`.
-
-Akihiro Suda <suda.kyoto@gmail.com> 
-Anand Patil <anand.prabhakar.patil@gmail.com> 
-Daniel Schep <dschep@gmail.com> 
-David Medberry <openstack@medberry.net> 
-Derek McGowan <derek@mcgstyle.net> 
-Eric Hotinger <ehotinger@gmail.com> 
-hansmi <hansmi@users.noreply.github.com> 
-Jessica Frazelle <acidburn@microsoft.com> 
-Matthew Fisher <matt.fisher@microsoft.com> 
-nogoegst <nogoegst@users.noreply.github.com> 
-Paul Tagliamonte <paultag@gmail.com> 
-Ryan Cox <ryancox@users.noreply.github.com> 
-Ryan Dunckel <sparty02@gmail.com>

vendor/github.com/genuinetools/img/LICENSE

@@ -1,21 +0,0 @@
-The MIT License (MIT)
-
-Copyright (c) 2018 The Genuinetools Authors
-
-Permission is hereby granted, free of charge, to any person obtaining a copy
-of this software and associated documentation files (the "Software"), to deal
-in the Software without restriction, including without limitation the rights
-to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-copies of the Software, and to permit persons to whom the Software is
-furnished to do so, subject to the following conditions:
-
-The above copyright notice and this permission notice shall be included in all
-copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-SOFTWARE.

vendor/github.com/genuinetools/img/types/types.go

@@ -1,10 +0,0 @@
-package types
-
-const (
-	// AutoBackend is automatically resolved into either overlayfs or native.
-	AutoBackend = "auto"
-	// NativeBackend defines the native backend.
-	NativeBackend = "native"
-	// OverlayFSBackend defines the overlayfs backend.
-	OverlayFSBackend = "overlayfs"
-)