Update dreamfactory/df-core requirement from ~0.16.3 to ~0.17.0

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@0.16.3...0.17.0)

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

Author: dependabot-preview[bot]

composer.json

@@ -29,7 +29,7 @@
   },
   "prefer-stable": true,
   "require":           {
-    "dreamfactory/df-core": "~0.16.3"
+    "dreamfactory/df-core": "~0.17.0"
   },
   "autoload":          {
     "psr-4": {