Bump deepmerge from 2.2.1 to 4.2.2

Bumps [deepmerge](https://github.com/TehShrike/deepmerge) from 2.2.1 to 4.2.2.
- [Release notes](https://github.com/TehShrike/deepmerge/releases)
- [Changelog](https://github.com/TehShrike/deepmerge/blob/master/changelog.md)
- [Commits](TehShrike/deepmerge@v2.2.1...v4.2.2)

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

package.json

@@ -70,7 +70,7 @@
   "dependencies": {
     "@2fd/command": "^1.1.2",
     "bluebird": "^3.5.5",
-    "deepmerge": "^2.0.1",
+    "deepmerge": "^4.2.2",
     "fs-extra": "^0.30.0",
     "glob": "^7.1.0",
     "graphql": "^0.12.0",