chore(package): update @types/node to version 13.9.6

Closes #7

Author: greenkeeper[bot]

package.json

@@ -21,7 +21,7 @@
     "@commitlint/cli": "7.5.2",
     "@commitlint/config-conventional": "7.5.0",
     "@types/chai": "4.1.7",
-    "@types/node": "11.9.3",
+    "@types/node": "13.9.6",
     "chai": "4.2.0",
     "chai-as-promised": "7.1.1",
     "commitizen": "3.0.5",