Bump underscore from 1.13.6 to 1.13.7 in /job-dsl-plugin

Bumps [underscore](https://github.com/jashkenas/underscore) from 1.13.6 to 1.13.7.
- [Commits](jashkenas/underscore@1.13.6...1.13.7)

---
updated-dependencies:
- dependency-name: underscore
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

job-dsl-plugin/package.json

@@ -26,7 +26,7 @@
     "jquery-ui": "1.14.0",
     "jquery.ui.layout": "1.1.0",
     "jstree": "3.3.16",
-    "underscore": "1.13.6"
+    "underscore": "1.13.7"
   },
   "devDependencies": {
     "copy-webpack-plugin": "12.0.2",