Enable support for Node.js 8

Author: rosen-vladimirov

package.json

@@ -42,6 +42,6 @@
     "typescript": "2.1.4"
   },
   "engines": {
-    "node": ">=4.2.1 <5.0.0 || >=5.1.0 <8.0.0"
+    "node": ">=4.2.1 <5.0.0 || >=5.1.0 <9.0.0"
   }
 }