Introduce logging

Change-Id: I5ac91cc195a46d666714904b56e9f89f56f9c2c0
diff --git a/composer.json b/composer.json
index 98cb9e4..cbe00da 100644
--- a/composer.json
+++ b/composer.json
@@ -1,5 +1,6 @@
 {
     "require": {
-        "gregwar/captcha": "1.*"
+        "gregwar/captcha": "1.*",
+        "monolog/monolog": "3.*"
     }
 }