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": "~3.0.0",