build(deps-dev): bump tslint from 5.20.1 to 6.1.2

Bumps [tslint](https://github.com/palantir/tslint) from 5.20.1 to 6.1.2.
- [Release notes](https://github.com/palantir/tslint/releases)
- [Changelog](https://github.com/palantir/tslint/blob/master/CHANGELOG.md)
- [Commits](palantir/tslint@5.20.1...6.1.2)

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

package.json

@@ -33,7 +33,7 @@
     "jest-config": "^24.9.0",
     "rimraf": "^3.0.0",
     "ts-jest": "^24.3.0",
-    "tslint": "^5.20.1",
+    "tslint": "^6.1.2",
     "typescript": "^3.7.4"
   },
   "dependencies": {}