Revert "feat(@angular/cli): add language service in devDependencies section"

This reverts commit 9eabfdd.

Author: hansl

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

@@ -27,7 +27,6 @@
   "devDependencies": {
     "@angular/cli": "<%= version %>",
     "@angular/compiler-cli": "^4.0.0",
-    "@angular/language-service": "^4.0.0",
     "@types/jasmine": "2.5.38",
     "@types/node": "~6.0.60",
     "codelyzer": "~2.0.0",