Upgrade Atomix to 2.0.8 and simplify consistent primitive operation/event IDs

Change-Id: I33b68a134a7f3d016a8947bffc3cea0b90bd4bd2
diff --git a/core/store/primitives/pom.xml b/core/store/primitives/pom.xml
index f6966ea..0974dc5 100644
--- a/core/store/primitives/pom.xml
+++ b/core/store/primitives/pom.xml
@@ -70,7 +70,7 @@
         <dependency>
             <groupId>io.atomix</groupId>
             <artifactId>atomix</artifactId>
-            <version>2.0.4</version>
+            <version>2.0.8</version>
         </dependency>
 
         <dependency>