Bump lodash from 4.17.4 to 4.17.21

Bumps [lodash](https://github.com/lodash/lodash) from 4.17.4 to 4.17.21.
- [Release notes](https://github.com/lodash/lodash/releases)
- [Commits](lodash/lodash@4.17.4...4.17.21)

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

package.json

@@ -42,7 +42,7 @@
     "grunt-sync": "0.2.4",
     "grunt-version-assets": "^1.1.0",
     "include-all": "~0.1.6",
-    "lodash": "^4.13.1",
+    "lodash": "^4.17.21",
     "marked": "^0.3.5",
     "md5": "^2.1.0",
     "morgan": "^1.8.1",