chore: release 1.5.0 (#335)

* updated CHANGELOG.md [ci skip]

* updated package.json [ci skip]

* updated samples/package.json [ci skip]

Author: yoshi-automation

dlp/package.json

@@ -15,7 +15,7 @@
     "test": "mocha system-test/*.test.js --timeout=600000"
   },
   "dependencies": {
-    "@google-cloud/dlp": "^1.4.0",
+    "@google-cloud/dlp": "^1.5.0",
     "@google-cloud/pubsub": "^0.32.0",
     "mime": "^2.3.1",
     "yargs": "^14.0.0"