fix(@angular/cli): language-service as devDeps only (#6257)

Author: cexbrayat

packages/@angular/cli/blueprints/ng/files/package.json

@@ -18,7 +18,6 @@
     "@angular/core": "^4.0.0",
     "@angular/forms": "^4.0.0",
     "@angular/http": "^4.0.0",
-    "@angular/language-service": "^4.0.0",
     "@angular/platform-browser": "^4.0.0",
     "@angular/platform-browser-dynamic": "^4.0.0",
     "@angular/router": "^4.0.0",