chore(package): update @angular/cli to version 1.7.3

Closes #3

Author: greenkeeper[bot]

package.json

@@ -35,7 +35,7 @@
     "zone.js": "^0.8.4"
   },
   "devDependencies": {
-    "@angular/cli": "1.2.4",
+    "@angular/cli": "1.7.3",
     "@angular/compiler-cli": "^4.0.0",
     "@angular/language-service": "^4.0.0",
     "@types/jasmine": "2.5.53",