fix: upgrade lodash from 4.17.20 to 4.17.21

Snyk has created this PR to upgrade lodash from 4.17.20 to 4.17.21.

See this package in npm:
https://www.npmjs.com/package/lodash

See this project in Snyk:
https://app.snyk.io/org/postman/project/8519ba8e-6a7d-469a-88b3-7891b4c1c14e?utm_source=github&utm_medium=upgrade-pr

Author: snyk-bot

package-lock.json

@@ -46,7 +46,7 @@
     "newman": "5.2.0",
     "jsdoc": "3.6.6",
     "mocha": "5.2.0",
-    "lodash": "4.17.20",
+    "lodash": "4.17.21",
     "nyc": "14.1.1",
     "parse-gitignore": "1.0.1",
     "pretty-ms": "3.2.0",