chore(deps): update dependency typescript to v2.7.1

Author: renovate-bot

package.json

@@ -20,6 +20,6 @@
   "devDependencies": {
     "@types/node": "8.5.7",
     "tslint": "5.8.0",
-    "typescript": "2.6.2"
+    "typescript": "2.7.1"
   }
 }