fix(@angular/cli): Set uglify plugin minimum to 1.1.5

 - Pins uglify-es dependency version on the Webpack side for #8997

Author: joshwiens

package-lock.json

@@ -92,7 +92,7 @@
     "stylus-loader": "^3.0.1",
     "tree-kill": "^1.0.0",
     "typescript": "~2.4.2",
-    "uglifyjs-webpack-plugin": "~1.1.2",
+    "uglifyjs-webpack-plugin": "^1.1.5",
     "url-loader": "^0.6.2",
     "webpack": "~3.10.0",
     "webpack-dev-middleware": "~1.12.0",