Update dependency @angular/cli to v6

Author: renovate-bot

doc/package.json

@@ -33,7 +33,7 @@
         "zone.js": "^0.8.14"
     },
     "devDependencies": {
-        "@angular/cli": "1.6.3",
+        "@angular/cli": "6.1.5",
         "@angular/compiler-cli": "5.1.2",
         "@angular/language-service": "^5.0.0",
         "typescript": "~2.4.2"