Bump underscore.string from 3.1.1 to 3.3.5

Bumps [underscore.string](https://github.com/epeli/underscore.string) from 3.1.1 to 3.3.5.
- [Release notes](https://github.com/epeli/underscore.string/releases)
- [Changelog](https://github.com/esamattis/underscore.string/blob/master/CHANGELOG.markdown)
- [Commits](esamattis/underscore.string@3.1.1...3.3.5)

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

package-lock.json

@@ -20,6 +20,6 @@
 		"load-grunt-tasks": "~3.2.0",
 		"time-grunt": "~1.2.1",
 		"underscore": "~1.8.3",
-		"underscore.string": "~3.1.1"
+		"underscore.string": "~3.3.5"
 	}
 }