chore(package): update @types/sinon to version 9.0.3

Closes #39

Author: greenkeeper[bot]

package.json

@@ -60,7 +60,7 @@
         "@types/i18next": "^12.1.0",
         "@types/i18next-xhr-backend": "^1.4.1",
         "@types/mocha": "^5.2.1",
-        "@types/sinon": "^7.0.5",
+        "@types/sinon": "^9.0.3",
         "bluebird": "^3.5.3",
         "browserify-versionify": "^1.0.6",
         "chai": "^4.2.0",