Bump lodash from 4.17.13 to 4.17.15

Bumps [lodash](https://github.com/lodash/lodash) from 4.17.13 to 4.17.15.
- [Release notes](https://github.com/lodash/lodash/releases)
- [Commits](https://github.com/lodash/lodash/compare/4.17.13...4.17.15)

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

package.json

@@ -45,7 +45,7 @@
     "create-react-class": "^15.6.3",
     "express": "^4.13.3",
     "jwt-simple": "^0.5.1",
-    "lodash": "^4.17.13",
+    "lodash": "^4.17.15",
     "marked": "^0.3.5",
     "moment": "^2.11.0",
     "mongoose": "^5.0.13",