Revert "Try Ehcache"

This reverts commit b7f4bb7ee472eb5202fbf17c415b8ddd2d68257f.
diff --git a/pom.xml b/pom.xml
index 93f05ba..6466062 100644
--- a/pom.xml
+++ b/pom.xml
@@ -159,9 +159,10 @@
         </dependency>
         <!-- https://mvnrepository.com/artifact/net.openhft/chronicle-map -->
         <dependency>
-            <groupId>org.ehcache</groupId>
-            <artifactId>ehcache</artifactId>
-            <version>3.8.1</version>
+            <scope>compile</scope>
+            <groupId>net.openhft</groupId>
+            <artifactId>chronicle-map</artifactId>
+            <version>3.17.8</version>
         </dependency>
     </dependencies>
 </project>
\ No newline at end of file