Update dreamfactory/df-core requirement from ~0.24 to ~0.25

Updates the requirements on [dreamfactory/df-core](https://github.com/dreamfactorysoftware/df-core) to permit the latest version.
- [Release notes](https://github.com/dreamfactorysoftware/df-core/releases)
- [Changelog](https://github.com/dreamfactorysoftware/df-core/blob/master/CHANGELOG.md)
- [Commits](dreamfactorysoftware/df-core@0.24.0...0.25.0)

---
updated-dependencies:
- dependency-name: dreamfactory/df-core
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

composer.json

@@ -31,7 +31,7 @@
   "minimum-stability": "dev",
   "prefer-stable":     true,
   "require":     {
-    "dreamfactory/df-core": "~0.24",
+    "dreamfactory/df-core": "~0.25",
     "guzzlehttp/guzzle":    "~6.0"
   },
   "require-dev": {