chore: release 2.2.0 (#320)

🤖 I have created a release \*beep\* \*boop\* 
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## [2.2.0](https://www.github.com/googleapis/nodejs-scheduler/compare/v2.1.3...v2.2.0) (2021-01-09)


### Features

* introduces style enumeration ([#318](https://www.github.com/googleapis/nodejs-scheduler/issues/318)) ([173b34e](https://www.github.com/googleapis/nodejs-scheduler/commit/173b34ebaa92cdfb402e66ccca7b37d68bc35ddd))
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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).

Author: release-please[bot]

scheduler/package.json

@@ -14,7 +14,7 @@
     "test": "mocha --timeout 10000 --exit"
   },
   "dependencies": {
-    "@google-cloud/scheduler": "^2.1.3",
+    "@google-cloud/scheduler": "^2.2.0",
     "body-parser": "^1.18.3",
     "express": "^4.16.4"
   },