Bump lodash from 4.17.19 to 4.17.21

Bumps [lodash](https://github.com/lodash/lodash) from 4.17.19 to 4.17.21.
- [Release notes](https://github.com/lodash/lodash/releases)
- [Commits](lodash/lodash@4.17.19...4.17.21)

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

Author: dependabot[bot]

package-lock.json

@@ -22,7 +22,7 @@
     "gatsby-source-filesystem": "^2.0.26",
     "gatsby-transformer-remark": "^2.6.9",
     "gatsby-transformer-sharp": "^2.1.9",
-    "lodash": "^4.17.19",
+    "lodash": "^4.17.21",
     "lodash-webpack-plugin": "^0.11.4",
     "netlify-cms-app": "^2.9.6",
     "node-sass": "^4.11.0",