Merge pull request #25 from appuio/renovate/monolog-monolog-3.x

Update dependency monolog/monolog to 3.4.*

Author: chrira

app/composer.json

@@ -1,5 +1,5 @@
 {
     "require": {
-        "monolog/monolog": "3.3.*"
+        "monolog/monolog": "3.4.*"
     }
 }