chore: release 3.0.0 (#248)

* updated CHANGELOG.md

* updated package.json

* updated samples/package.json

Author: yoshi-automation

cloud-language/snippets/package.json

@@ -17,7 +17,7 @@
   "dependencies": {
     "@google-cloud/automl": "^1.0.0",
     "mathjs": "^5.1.0",
-    "@google-cloud/language": "^2.1.0",
+    "@google-cloud/language": "^3.0.0",
     "@google-cloud/storage": "^2.0.0",
     "yargs": "^13.0.0"
   },