Bump underscore.string from 3.3.4 to 3.3.5
Bump underscore.string from 3.3.4 to 3.3.5

Bumps [underscore.string](https://github.com/epeli/underscore.string) from 3.3.4 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](https://github.com/epeli/underscore.string/compare/3.3.4...3.3.5)

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>
stefanpenner/ember-inflector,stefanpenner/ember-inflector