chore(package): update @types/sinon to version 9.0.4

Closes #112

Author: greenkeeper[bot]

package.json

@@ -40,7 +40,7 @@
     "@types/chai": "^4.1.6",
     "@types/chai-as-promised": "^7.1.0",
     "@types/mocha": "^5.2.5",
-    "@types/sinon": "^5.0.2",
+    "@types/sinon": "^9.0.4",
     "chai": "^4.2.0",
     "chai-as-promised": "^7.1.1",
     "coveralls": "^3.0.2",