Bump sinon from 8.0.4 to 8.1.1 (#2440)

Bumps [sinon](https://github.com/sinonjs/sinon) from 8.0.4 to 8.1.1.
- [Release notes](https://github.com/sinonjs/sinon/releases)
- [Changelog](https://github.com/sinonjs/sinon/blob/master/CHANGELOG.md)
- [Commits](sinonjs/sinon@v8.0.4...v8.1.1)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Author: dependabot-preview[bot]

package-lock.json

@@ -63,7 +63,7 @@
     "mocha-multi-reporters": "~1.1.7",
     "mock-fs": "~4.10.4",
     "rewire": "~4.0.1",
-    "sinon": "~8.0.4",
+    "sinon": "~8.1.1",
     "tslint": "~5.20.1",
     "typescript": "~3.5.3",
     "vsce": "~1.64.0",