Updates to zipkin-java 0.5

This includes better dependency aggregation than before. For example,
you no longer need mysql to view the dependency graph, as the in-memory
server supports aggregation now. Also, if you log "ca" on a root span,
the associated service will show on the dependency graph on the far
left. This allows you to show uninstrumented clients of note. Similarly,
if you log "sa" on a leaf node, the destination will show on the far
right. You'd use "sa" for uninstrumented services like databases, auth
servers or cloud apis.

Note: 0.5.2 uses spring boot 1.3.2

spring-cloud-sleuth-samples/pom.xml

@@ -62,12 +62,12 @@
 			<dependency>
 				<groupId>io.zipkin.java</groupId>
 				<artifactId>zipkin</artifactId>
-				<version>0.4.4</version>
+				<version>0.5.2</version>
 			</dependency>
 			<dependency>
 				<groupId>io.zipkin.java</groupId>
 				<artifactId>zipkin-server</artifactId>
-				<version>0.4.4</version>
+				<version>0.5.2</version>
 			</dependency>
 		</dependencies>
 	</dependencyManagement>