chore(package): update sinon to version 7.5.0

Closes #106

Author: greenkeeper[bot]

package.json

@@ -60,7 +60,7 @@
     "mocha": "^5.1.1",
     "mocha-typescript": "^1.1.14",
     "nyc": "^12.0.2",
-    "sinon": "^6.0.1",
+    "sinon": "^7.5.0",
     "ts-node": "^7.0.1",
     "tslint": "^5.10.0",
     "tslint-config-standard": "^8.0.0",