chore: release 5.1.0 (#391)

* updated CHANGELOG.md [ci skip]

* updated package.json [ci skip]

* updated samples/package.json [ci skip]

Author: release-please[bot]

translate/package.json

@@ -16,7 +16,7 @@
   "dependencies": {
     "@google-cloud/automl": "^1.0.0",
     "@google-cloud/text-to-speech": "^1.1.4",
-    "@google-cloud/translate": "^5.0.2",
+    "@google-cloud/translate": "^5.1.0",
     "@google-cloud/vision": "^1.2.0",
     "yargs": "^15.0.0"
   },