update

src/main/resources/logback.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<configuration debug="false">
+    <!-- definition of appender STDOUT -->
+    <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+        <encoder>
+            <pattern>%-4relative [%thread] %-5level %logger{35} - %msg %n</pattern>
+        </encoder>
+    </appender>
+
+    <root level="ERROR">
+        <!-- appender referenced after it is defined -->
+        <appender-ref ref="STDOUT"/>
+    </root>
+</configuration>