Update maven coordinates in README (#110)

diff --git a/README.adoc b/README.adoc
index 3f0946c..82bea24 100644
--- a/README.adoc
+++ b/README.adoc
@@ -123,7 +123,7 @@
     </dependency>
     <dependency>
         <groupId>org.apache.pulsar</groupId>
-        <artifactId>reactive-pulsar-producer-cache-caffeine</artifactId>
+        <artifactId>pulsar-client-reactive-producer-cache-caffeine</artifactId>
         <version>0.1.0-SNAPSHOT</version>
     </dependency>
 </dependencies>