test: include conversionRule for clr keyword

src/main/resources/logback-spring.xml

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <configuration>
     <include resource="org/springframework/boot/logging/logback/defaults.xml"/>
+    <conversionRule conversionWord="clr" converterClass="org.springframework.boot.logging.logback.ColorConverter" />
     <springProperty name="application_name" source="spring.application.name"/>
 
     <statusListener class="ch.qos.logback.core.status.OnConsoleStatusListener"/>