Add Pub/Sub synth.metadata (#4194)

Author: yoshi-automation

google-cloud-clients/google-cloud-pubsub/synth.metadata

@@ -0,0 +1,32 @@
+{
+  "updateTime": "2018-12-07T08:45:57.038583Z",
+  "sources": [
+    {
+      "generator": {
+        "name": "artman",
+        "version": "0.16.2",
+        "dockerImage": "googleapis/artman@sha256:2f6b261ee7fe1aedf238991c93a20b3820de37a343d0cacf3e3e9555c2aaf2ea"
+      }
+    },
+    {
+      "git": {
+        "name": "googleapis",
+        "remote": "https://github.com/googleapis/googleapis.git",
+        "sha": "200fbbe59cc7b0077ae525eb5f3d6420c0c53e61",
+        "internalRef": "224174014"
+      }
+    }
+  ],
+  "destinations": [
+    {
+      "client": {
+        "source": "googleapis",
+        "apiName": "pubsub",
+        "apiVersion": "v1",
+        "language": "java",
+        "generator": "gapic",
+        "config": "google/pubsub/artman_pubsub.yaml"
+      }
+    }
+  ]
+}