Pruned duplicate dependencies and plugins from several core related pom.xml files.
diff --git a/core/pom.xml b/core/pom.xml
index afee0d0..c0f74cf 100644
--- a/core/pom.xml
+++ b/core/pom.xml
@@ -20,6 +20,7 @@
         <module>api</module>
         <module>net</module>
         <module>store</module>
+        <module>json</module>
     </modules>
 
     <dependencies>