skip memefficiency tests in CI as they are inconsistent (#250)

Author: msotheeswaran-sc

Diff for: build.yaml

@@ -21,7 +21,7 @@ machamp:
         parent: make-build
         # https://github.sc-corp.net/Snapchat/img/tree/master/keydb/ubuntu-20-04
         builder_image: us.gcr.io/snapchat-build-artifacts/prod/snapchat/img/keydb/keydb-ubuntu-20-04@sha256:cf869a3f5d1de1e1d976bb906689c37b7031938eb68661b844a38c532f27248c
-        command: ./runtest --clients 4 --verbose --tls
+        command: ./runtest --clients 4 --verbose --tls --skipunit unit/memefficiency
       cluster-test:
         type: cmd
         parent: make-build