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] <[email protected]>

Author: dependabot[bot]

package-lock.json

@@ -10,7 +10,7 @@
     "chart.js": "^2.9.4",
     "core-js": "^3.3.2",
     "firebase": "^7.10.0",
-    "lodash": "^4.17.15",
+    "lodash": "^4.17.21",
     "materialize-css": "^1.0.0-rc.2",
     "register-service-worker": "^1.6.2",
     "vue": "^2.6.10",