Adapt to logging changes

- Moving over to log4j2 for test logging.
- Need to follow what happens to commons-logging
  per SPR-14512.
- Relates to #394

spring-statemachine-samples/tasks/src/test/resources/log4j.properties

@@ -1,8 +0,0 @@
-log4j.rootCategory=INFO, stdout
-
-log4j.appender.stdout=org.apache.log4j.ConsoleAppender
-log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
-log4j.appender.stdout.layout.ConversionPattern=%d{ABSOLUTE} %5p %t %c{2} [%t] - %m%n
-
-log4j.category.org.springframework.statemachine=TRACE
-

spring-statemachine-samples/tasks/src/test/resources/log4j2.xml

@@ -0,0 +1,13 @@
+<Configuration>
+		<Appenders>
+				<Console name="STDOUT" target="SYSTEM_OUT">
+						<PatternLayout pattern="%d{ABSOLUTE} %5p %t %c{2} [%t] - %m%n"/>
+				</Console>
+		</Appenders>
+		<Loggers>
+				<Logger name="org.springframework.statemachine" level="debug"/>
+				<Root level="info">
+						<AppenderRef ref="STDOUT"/>
+				</Root>
+		</Loggers>
+</Configuration>