hotfix: update dependency version

Author: Samffy

composer.json

@@ -12,7 +12,7 @@
     "require": {
         "php": ">=5.5.0",
         "symfony/event-dispatcher": "~2.5|~3.0|~4.0",
-        "fulll/command-bus": "^3.4"
+        "fulll/command-bus": "^3.4.4"
     },
     "repositories": [
         { "type": "git", "url": "[email protected]:fulll/command-bus.git" }