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] <[email protected]>

Author: dependabot[bot]

package.json

@@ -58,7 +58,7 @@
         "isomorphic-fetch": "^2.2.1",
         "json2csv": "^4.5.2",
         "jsonwebtoken": "^8.5.1",
-        "lodash": "^4.17.19",
+        "lodash": "^4.17.21",
         "mailchimp-api-v3": "^1.13.1",
         "mailgun-js": "^0.22.0",
         "mailgun.js": "^3.5.9",