chore: release 1.2.4 (#219)

* updated CHANGELOG.md [ci skip]

* updated package.json [ci skip]

* updated samples/package.json [ci skip]

Author: yoshi-automation

automl/package.json

@@ -18,7 +18,7 @@
     "test": "mocha --timeout 600000"
   },
   "dependencies": {
-    "@google-cloud/automl": "^1.2.3",
+    "@google-cloud/automl": "^1.2.4",
     "chai": "^4.2.0",
     "csv": "^5.1.1",
     "execa": "^2.0.0",