Update path-exists requirement from ^3.0.0 to ^4.0.0

Updates the requirements on [path-exists](https://github.com/sindresorhus/path-exists) to permit the latest version.
- [Release notes](https://github.com/sindresorhus/path-exists/releases)
- [Commits](sindresorhus/path-exists@v3.0.0...v4.0.0)

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

packages/ucf-cli/package.json

@@ -34,7 +34,7 @@
     "glob": "^7.1.3",
     "inquirer": "^6.2.1",
     "minimist": "^1.2.0",
-    "path-exists": "^3.0.0",
+    "path-exists": "^4.0.0",
     "request": "^2.88.0",
     "single-line-log": "^1.1.2",
     "str-format": "^1.0.1"