Bump slim/slim from 2.4.3 to 2.6.0

Bumps [slim/slim](https://github.com/slimphp/Slim) from 2.4.3 to 2.6.0.
- [Release notes](https://github.com/slimphp/Slim/releases)
- [Changelog](https://github.com/slimphp/Slim/blob/4.x/CHANGELOG.md)
- [Commits](slimphp/Slim@2.4.3...2.6.0)

---
updated-dependencies:
- dependency-name: slim/slim
  dependency-type: direct:production
...

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

composer.json

@@ -2,7 +2,7 @@
     "name": "uzulla/tinitter",
     "description": "sample web app",
     "require": {
-        "slim/slim": "2.4.*",
+        "slim/slim": "2.6.*",
         "slim/views": "0.1.*",
         "slim/extras": "2.0.*",
         "twig/twig": "1.*",