chore(package): update @types/node to version 9.4.4

Closes #25

Author: greenkeeper[bot]

package.json

@@ -39,7 +39,7 @@
     "@angular/compiler-cli": "^4.0.0",
     "@angular/language-service": "^4.0.0",
     "@types/jasmine": "2.5.53",
-    "@types/node": "~8.0.13",
+    "@types/node": "~9.4.4",
     "angular-cli-ghpages": "^0.5.1",
     "codelyzer": "~3.1.2",
     "jasmine-core": "~2.6.2",