chore: release 1.6.0 (#110)

* updated CHANGELOG.md [ci skip]

* updated package.json [ci skip]

* updated samples/package.json [ci skip]

Author: release-please[bot]

container-analysis/snippets/package.json

@@ -14,7 +14,7 @@
     "test": "mocha --timeout 100000 test/**.test.js"
   },
   "dependencies": {
-    "@google-cloud/containeranalysis": "^1.5.1",
+    "@google-cloud/containeranalysis": "^1.6.0",
     "@google-cloud/pubsub": "^1.0.0",
     "p-retry": "^4.1.0"
   },