vendor: add buildkit

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

vendor/github.com/moby/buildkit/AUTHORS

@@ -0,0 +1,56 @@
+# This file lists all individuals having contributed content to the repository.
+# For how it is generated, see `scripts/generate-authors.sh`.
+
+Aaron L. Xu <likexu@harmonycloud.cn>
+Aaron Lehmann <aaron.lehmann@docker.com>
+Akihiro Suda <suda.akihiro@lab.ntt.co.jp>
+Alexander Morozov <lk4d4@docker.com>
+Alice Frosi <afrosi@de.ibm.com>
+Allen Sun <allen.sun@daocloud.io>
+Anda Xu <anda.xu@docker.com>
+Anthony Sottile <asottile@umich.edu>
+Arnaud Bailly <arnaud.oqube@gmail.com>
+Bin Liu <liubin0329@gmail.com>
+Brian Goff <cpuguy83@gmail.com>
+Daniel Nephin <dnephin@gmail.com>
+David Calavera <david.calavera@gmail.com>
+Dennis Chen <dennis.chen@arm.com>
+Derek McGowan <derek@mcgstyle.net>
+Doug Davis <dug@us.ibm.com>
+Edgar Lee <edgarl@netflix.com>
+Eli Uriegas <eli.uriegas@docker.com>
+f0 <f0@users.noreply.github.com>
+Helen Xie <chenjg@harmonycloud.cn>
+Ian Campbell <ijc@docker.com>
+Jean-Pierre Huynh <jean-pierre.huynh@ounet.fr>
+Jessica Frazelle <acidburn@microsoft.com>
+John Howard <jhoward@microsoft.com>
+Jonathan Stoppani <jonathan.stoppani@divio.com>
+Justas Brazauskas <brazauskasjustas@gmail.com>
+Justin Cormack <justin.cormack@docker.com>
+Kunal Kushwaha <kushwaha_kunal_v7@lab.ntt.co.jp>
+Lajos Papp <lalyos@yahoo.com>
+Matt Rickard <mrick@google.com>
+Michael Crosby <crosbymichael@gmail.com>
+Miyachi Katsuya <miyachi_katsuya@r.recruit.co.jp>
+Nao YONASHIRO <yonashiro@r.recruit.co.jp>
+Noel Georgi <18496730+frezbo@users.noreply.github.com>
+Ondrej Fabry <ofabry@cisco.com>
+Ri Xu <xuri.me@gmail.com>
+Sebastiaan van Stijn <github@gone.nl>
+Shev Yan <yandong_8212@163.com>
+Simon Ferquel <simon.ferquel@docker.com>
+Stefan Weil <sw@weilnetz.de>
+Thomas Leonard <thomas.leonard@docker.com>
+Thomas Shaw <tomwillfixit@users.noreply.github.com>
+Tibor Vass <tibor@docker.com>
+Tiffany Jernigan <tiffany.f.j@gmail.com>
+Tino Rusch <tino.rusch@gmail.com>
+Tobias Klauser <tklauser@distanz.ch>
+Tomas Tomecek <ttomecek@redhat.com>
+Tõnis Tiigi <tonistiigi@gmail.com>
+Vincent Demeester <vincent.demeester@docker.com>
+Wei Fu <fuweid89@gmail.com>
+Yong Tang <yong.tang.github@outlook.com>
+Yuichiro Kaneko <spiketeika@gmail.com>
+郑泽宇 <perhapszzy@sina.com>