Bump underscore from 1.10.2 to 1.13.6

Bumps [underscore](https://github.com/jashkenas/underscore) from 1.10.2 to 1.13.6.
- [Commits](jashkenas/underscore@1.10.2...1.13.6)

---
updated-dependencies:
- dependency-name: underscore
  dependency-type: indirect
...

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

Author: dependabot[bot]