Add custom pipeline yaml for wider clippy coverage

Fixes #25.

Signed-off-by: Keiichi Watanabe <[email protected]>

.buildkite/pipeline.yml

@@ -0,0 +1,17 @@
+# Copyright 2021 The Chromium OS Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE-BSD-Google file.
+
+steps:
+ - label: "clippy-x86-custom"
+   commands:
+    - cargo clippy --all-features --all-targets --workspace -- -D warnings
+   retry:
+    automatic: false
+   agents:
+    platform: x86_64.metal
+    os: linux
+   plugins:
+    - docker#v3.0.1:
+       image: "rustvmm/dev:v11"
+       always-pull: true