chore: release 3.1.3 (#467)

🤖 I have created a release \*beep\* \*boop\* 
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### [3.1.3](https://www.github.com/googleapis/nodejs-text-to-speech/compare/v3.1.2...v3.1.3) (2020-11-25)


### Bug Fixes

* **browser:** check for fetch on window ([a0925b3](https://www.github.com/googleapis/nodejs-text-to-speech/commit/a0925b35d4e39587388cfe05685891d523f1bc49))
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This PR was generated with [Release Please](https://github.com/googleapis/release-please).

Author: release-please[bot]

texttospeech/package.json

@@ -14,7 +14,7 @@
     "test": "mocha --timeout=60000"
   },
   "dependencies": {
-    "@google-cloud/text-to-speech": "^3.1.2",
+    "@google-cloud/text-to-speech": "^3.1.3",
     "yargs": "^16.0.0"
   },
   "devDependencies": {