security: bump lodash to 4.17.21

Signed-off-by: Tim Hansen <timbonicus@gmail.com>

plugins/rollbar/package.json

@@ -40,7 +40,7 @@
     "@material-ui/core": "^4.12.2",
     "@material-ui/icons": "^4.9.1",
     "@material-ui/lab": "4.0.0-alpha.57",
-    "lodash": "^4.17.15",
+    "lodash": "^4.17.21",
     "react": "^16.13.1",
     "react-dom": "^16.13.1",
     "react-router": "6.0.0-beta.0",