chore(package): update @angular-builders/custom-webpack to version 2.5.0

Author: greenkeeper[bot]

package.json

@@ -64,7 +64,7 @@
     "zone.js": "^0.8.26"
   },
   "devDependencies": {
-    "@angular-builders/custom-webpack": "2.4.1",
+    "@angular-builders/custom-webpack": "2.5.0",
     "@angular-devkit/build-angular": "^0.8.1",
     "@angular/cli": "~6.2.1",
     "@angular/compiler-cli": "^6.1.7",