chore(deps): bump is-plain-object from 3.0.1 to 4.0.0

Bumps [is-plain-object](https://github.com/jonschlinkert/is-plain-object) from 3.0.1 to 4.0.0.
- [Release notes](https://github.com/jonschlinkert/is-plain-object/releases)
- [Commits](jonschlinkert/is-plain-object@v3.0.1...v4.0.0)

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

package.json

@@ -28,7 +28,7 @@
     "bluebird": "^3.2.2",
     "cuid": "^2.1.4",
     "graceful-fs": "^4.1.3",
-    "is-plain-object": "^3.0.0",
+    "is-plain-object": "^4.0.0",
     "rfdc": "^1.1.4"
   },
   "devDependencies": {