Moves to significantly more performant zipkin-reporter (#807)

Under load, the previous version of zipkin-reporter's AsyncReporter
caused a lot of overhead. This version fixes that by ensuring encoding
is deferred and not done inside a lock.

spring-cloud-sleuth-dependencies/pom.xml

@@ -14,9 +14,9 @@
 	<name>spring-cloud-sleuth-dependencies</name>
 	<description>Spring Cloud Sleuth Dependencies</description>
 	<properties>
-		<zipkin.version>2.3.1</zipkin.version>
+		<zipkin.version>2.4.1</zipkin.version>
 		<zipkin-reporter.version>1.1.2</zipkin-reporter.version>
-		<zipkin-reporter2.version>2.1.4</zipkin-reporter2.version>
+		<zipkin-reporter2.version>2.2.0</zipkin-reporter2.version>
 	</properties>
 	<dependencyManagement>
 		<dependencies>
@@ -69,7 +69,7 @@
 				<groupId>io.zipkin.java</groupId>
 				<artifactId>zipkin</artifactId>
 				<!-- misaligned intentionally https://github.com/spring-projects/spring-boot/issues/10778-->
-				<version>2.3.0</version>
+				<version>2.4.0</version>
 			</dependency>
 			<dependency>
 				<groupId>io.zipkin.zipkin2</groupId>

spring-cloud-sleuth-samples/pom.xml

@@ -57,7 +57,7 @@
 			<dependency>
 				<groupId>io.zipkin.zipkin2</groupId>
 				<artifactId>zipkin</artifactId>
-				<version>2.3.1</version>
+				<version>2.4.1</version>
 			</dependency>
 		</dependencies>
 	</dependencyManagement>

spring-cloud-sleuth-samples/spring-cloud-sleuth-sample-test-core/pom.xml

@@ -55,7 +55,7 @@
 			<plugin>
 				<groupId>org.codehaus.mojo</groupId>
 				<artifactId>animal-sniffer-maven-plugin</artifactId>
-				<version>1.14</version>
+				<version>1.16</version>
 				<configuration>
 					<skip>true</skip>
 					<signature>

spring-cloud-sleuth-zipkin/pom.xml

@@ -130,7 +130,7 @@
 		<dependency>
 			<groupId>com.squareup.okhttp3</groupId>
 			<artifactId>mockwebserver</artifactId>
-			<version>3.9.0</version>
+			<version>3.9.1</version>
 			<scope>test</scope>
 		</dependency>
 		<dependency>