chore: release 2.2.0 (#346)

Author: release-please[bot]

texttospeech/package.json

@@ -14,7 +14,7 @@
     "test": "mocha --timeout=60000"
   },
   "dependencies": {
-    "@google-cloud/text-to-speech": "^2.1.3",
+    "@google-cloud/text-to-speech": "^2.2.0",
     "yargs": "^15.0.0"
   },
   "devDependencies": {