[logdog] Begin migrating to Makefile.

logdog/appengine/cmd/coordinator/vmuser/cron.yaml

+# Copyright 2017 The LUCI Authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+cron:
+
+- description: "tsmon housekeeping task"
+  url: "/internal/cron/ts_mon/housekeeping"
+  schedule: "every 1 minutes"
+  target: backend
+
+# This cron task supports the refresh of the datastore cache every 10 minutes.
+- description: "LUCI Config datastore cache periodic refresh"
+  url: "/admin/config/cache/manager"
+  schedule: "every 10 minutes"
+  target: backend
+
+- description: "tumble fire_all_tasks invocation"
+  url: "/internal/tumble/fire_all_tasks"
+  schedule: "every 10 minutes"
+  target: backend