chore(package): update @types/node to version 13.7.7

Closes #59

Author: greenkeeper[bot]

package.json

@@ -35,7 +35,7 @@
         "@types/minimatch": "^3.0.3",
         "@types/mocha": "^5.2.7",
         "@types/mz": "0.0.32",
-        "@types/node": "^12.11.7",
+        "@types/node": "^13.7.7",
         "@types/sinon": "^7.5.0",
         "@types/sinon-chai": "^3.2.3",
         "chai": "^4.2.0",