Autoupdate dev dependencies (#8)

* Autoupdate dependencies

* Update only dev dependencies

Co-authored-by: Radek Hubner <[email protected]>

Author: olsavmic

.github/dependabot.yml

@@ -0,0 +1,10 @@
+version: 2
+updates:
+    -
+        package-ecosystem: "composer"
+        directory: "/"
+        schedule:
+            interval: "weekly"
+        open-pull-requests-limit: 5
+        allow:
+            - dependency-type: "development"