fix(deps): update dependency sinon to v6 (#516)

Author: renovate[bot]

package-lock.json

@@ -86,7 +86,7 @@
     "prettier": "1.14.2",
     "rimraf": "^2.6.1",
     "semantic-release": "^15.1.8",
-    "sinon": "^5.0.0",
+    "sinon": "^6.0.0",
     "source-map-support": "^0.5.0",
     "temp": "^0.8.3",
     "tslint": "^5.11.0",