chore: release 3.16.0 (#539)

🤖 I have created a release \*beep\* \*boop\*
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## [3.16.0](https://www.github.com/googleapis/nodejs-asset/compare/v3.15.5...v3.16.0) (2021-08-16)


### Features

* Release of relationships in v1, Add content type Relationship to support relationship export ([#537](https://www.github.com/googleapis/nodejs-asset/issues/537)) ([873aae6](https://www.github.com/googleapis/nodejs-asset/commit/873aae6f9b846a16b5695b692e8ad668d684dc6c))
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This PR was generated with [Release Please](https://github.com/googleapis/release-please). See [documentation](https://github.com/googleapis/release-please#release-please).

asset/snippets/package.json

@@ -15,7 +15,7 @@
     "test": "mocha --timeout 180000"
   },
   "dependencies": {
-    "@google-cloud/asset": "^3.15.5",
+    "@google-cloud/asset": "^3.16.0",
     "@google-cloud/bigquery": "^5.5.0",
     "@google-cloud/compute": "^2.0.0",
     "@google-cloud/storage": "^5.0.0",