Add minimal CircleCI config

We need to add this to the private repo so it is not clobbered on release to OSS. Unfortunately, we cannot stop CircleCI from failing builds on the `orion` branch without a config

Author: zanieb

.circleci/config.yml

@@ -0,0 +1,9 @@
+version: 2.1
+
+jobs:
+  build:  # must be called 'build' if not using a workflow
+    docker:
+      - image: alpine:latest
+
+    steps:
+      - run: echo "looks good to me!"