Add multi-project pipeline to server

This allows us to properly test changes made as MRs here using the same pipeline
we use for cinc-project/distribution/auditor via the multi-project pipeline
feature [1].

[1] https://docs.gitlab.com/ee/ci/multi_project_pipelines.html

Signed-off-by: Lance Albertson <lance@osuosl.org>

.gitlab-ci.yml

@@ -0,0 +1,16 @@
+---
+stages:
+  - test
+
+workflow:
+  rules:
+    # Run if this is a merge request
+    - if: $CI_MERGE_REQUEST_ID
+
+server-testing:
+  stage: test
+  variables:
+    CINC_REF: $CI_COMMIT_REF_NAME
+  trigger:
+    project: cinc-project/distribution/auditor
+    strategy: depend