Bump lodash from 4.17.15 to 4.17.21

Bumps [lodash](https://github.com/lodash/lodash) from 4.17.15 to 4.17.21.
- [Release notes](https://github.com/lodash/lodash/releases)
- [Commits](lodash/lodash@4.17.15...4.17.21)

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

Author: dependabot[bot]

package-lock.json

@@ -47,7 +47,7 @@
     "eslint-plugin-node": "^11.1.0",
     "eslint-plugin-prettier": "^4.0.0",
     "jest": "24.8.0",
-    "lodash": "4.17.15",
+    "lodash": "4.17.21",
     "math-expression-evaluator": "1.2.17",
     "prettier": "^2.4.1",
     "rollup": "^2.77.2",