Bump @types/node dependency. Tests on node 6 were doing this anyway because ancient npm does not respect package-lock.json

Author: cspotcode

package-lock.json

@@ -58,7 +58,7 @@
     "@types/chai": "^4.0.4",
     "@types/diff": "^4.0.2",
     "@types/mocha": "^5.2.7",
-    "@types/node": "^13.9.2",
+    "@types/node": "^13.13.1",
     "@types/proxyquire": "^1.3.28",
     "@types/react": "^16.0.2",
     "@types/semver": "^7.1.0",