chore(package): update sinon to version 9.0.2

Closes #312

Author: greenkeeper[bot]

package.json

@@ -60,7 +60,7 @@
     "express": "^4.16.4",
     "mocha": "^6.1.1",
     "nyc": "^15.0.0",
-    "sinon": "^7.2.4",
+    "sinon": "^9.0.2",
     "sinon-chai": "^3.3.0",
     "tsd": "^0.8.0",
     "typescript": "^3.6.3"