migrate to go modules from vndr

Signed-off-by: Tariq Ibrahim <tariq181290@gmail.com>

vendor/github.com/opencontainers/go-digest/.pullapprove.yml

@@ -0,0 +1,12 @@
+approve_by_comment: true
+approve_regex: '^(Approved|lgtm|LGTM|:shipit:|:star:|:\+1:|:ship:)'
+reject_regex: ^Rejected
+reset_on_push: true
+author_approval: ignored
+signed_off_by:
+  required: true
+reviewers:
+  teams:
+  - go-digest-maintainers
+  name: default
+  required: 2

vendor/github.com/opencontainers/go-digest/.travis.yml

@@ -0,0 +1,4 @@
+language: go
+go:
+  - 1.7
+  - master

vendor/github.com/opencontainers/go-digest/CONTRIBUTING.md

@@ -0,0 +1,72 @@
+# Contributing to Docker open source projects
+
+Want to hack on this project? Awesome! Here are instructions to get you started.
+
+This project is a part of the [Docker](https://www.docker.com) project, and follows
+the same rules and principles. If you're already familiar with the way
+Docker does things, you'll feel right at home.
+
+Otherwise, go read Docker's
+[contributions guidelines](https://github.com/docker/docker/blob/master/CONTRIBUTING.md),
+[issue triaging](https://github.com/docker/docker/blob/master/project/ISSUE-TRIAGE.md),
+[review process](https://github.com/docker/docker/blob/master/project/REVIEWING.md) and
+[branches and tags](https://github.com/docker/docker/blob/master/project/BRANCHES-AND-TAGS.md).
+
+For an in-depth description of our contribution process, visit the
+contributors guide: [Understand how to contribute](https://docs.docker.com/opensource/workflow/make-a-contribution/)
+
+### Sign your work
+
+The sign-off is a simple line at the end of the explanation for the patch. Your
+signature certifies that you wrote the patch or otherwise have the right to pass
+it on as an open-source patch. The rules are pretty simple: if you can certify
+the below (from [developercertificate.org](http://developercertificate.org/)):
+
+```
+Developer Certificate of Origin
+Version 1.1
+
+Copyright (C) 2004, 2006 The Linux Foundation and its contributors.
+1 Letterman Drive
+Suite D4700
+San Francisco, CA, 94129
+
+Everyone is permitted to copy and distribute verbatim copies of this
+license document, but changing it is not allowed.
+
+
+Developer's Certificate of Origin 1.1
+
+By making a contribution to this project, I certify that:
+
+(a) The contribution was created in whole or in part by me and I
+    have the right to submit it under the open source license
+    indicated in the file; or
+
+(b) The contribution is based upon previous work that, to the best
+    of my knowledge, is covered under an appropriate open source
+    license and I have the right under that license to submit that
+    work with modifications, whether created in whole or in part
+    by me, under the same open source license (unless I am
+    permitted to submit under a different license), as indicated
+    in the file; or
+
+(c) The contribution was provided directly to me by some other
+    person who certified (a), (b) or (c) and I have not modified
+    it.
+
+(d) I understand and agree that this project and the contribution
+    are public and that a record of the contribution (including all
+    personal information I submit with it, including my sign-off) is
+    maintained indefinitely and may be redistributed consistent with
+    this project or the open source license(s) involved.
+```
+
+Then you just add a line to every git commit message:
+
+    Signed-off-by: Joe Smith <joe.smith@email.com>
+
+Use your real name (sorry, no pseudonyms or anonymous contributions.)
+
+If you set your `user.name` and `user.email` git configs, you can sign your
+commit automatically with `git commit -s`.

vendor/github.com/opencontainers/go-digest/MAINTAINERS

@@ -0,0 +1,7 @@
+Brandon Philips <brandon.philips@coreos.com> (@philips)
+Brendan Burns <bburns@microsoft.com> (@brendandburns)
+Jason Bouzane <jbouzane@google.com> (@jbouzane)
+John Starks <jostarks@microsoft.com> (@jstarks)
+Jonathan Boulle <jon.boulle@coreos.com> (@jonboulle)
+Stephen Day <stephen.day@docker.com> (@stevvooe)
+Vincent Batts <vbatts@redhat.com> (@vbatts)