fix(@angular-devkit/schematics): remove unused dependency

Author: filipesilva

packages/angular_devkit/schematics/package.json

@@ -17,7 +17,6 @@
   ],
   "dependencies": {
     "@angular-devkit/core": "0.0.0",
-    "@ngtools/json-schema": "^1.1.0",
     "rxjs": "^6.0.0-beta.3"
   }
 }