Creating persistence service.

Change-Id: Ib78b4001a24c71b4096e5a2a446dbd5009aa1090
diff --git a/core/api/pom.xml b/core/api/pom.xml
index 23a051c..c01ebf1 100644
--- a/core/api/pom.xml
+++ b/core/api/pom.xml
@@ -63,6 +63,11 @@
             <artifactId>onlab-rest</artifactId>
             <version>${project.version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.mapdb</groupId>
+            <artifactId>mapdb</artifactId>
+            <version>1.0.8</version>
+        </dependency>
     </dependencies>
 
 </project>