chore(package): update dependencies (#347)

Author: greenkeeper[bot]

package.json

@@ -100,7 +100,7 @@
     "gulp": "^4.0.0",
     "mocha": "^5.1.1",
     "pre-commit": "^1.1.3",
-    "sinon": "^6.0.0",
+    "sinon": "^7.2.3",
     "unorm": "^1.4.1",
     "uuid": "^3.3.2"
   },