chore(package): update sinon to version 7.5.0

Closes #185

Author: greenkeeper[bot]

package.json

@@ -95,7 +95,7 @@
     "react-test-renderer": "^16.1.1",
     "redux-devtools": "^3.4.1",
     "redux-mock-store": "^1.3.0",
-    "sinon": "^4.1.3",
+    "sinon": "^7.5.0",
     "surge": "^0.19.0"
   }
 }