Moved generic Timestamp/ClockManager classes to onos-api
so they are usable by applications.

Change-Id: Icf0e92d12434dec782332e91b632da8066a85b60
diff --git a/core/store/dist/src/test/java/org/onosproject/store/impl/WallClockTimestampTest.java b/core/store/dist/src/test/java/org/onosproject/store/impl/WallClockTimestampTest.java
index c0fda9e..ead4612 100644
--- a/core/store/dist/src/test/java/org/onosproject/store/impl/WallClockTimestampTest.java
+++ b/core/store/dist/src/test/java/org/onosproject/store/impl/WallClockTimestampTest.java
@@ -24,6 +24,7 @@
 import org.onlab.util.KryoNamespace;
 
 import com.google.common.testing.EqualsTester;
+import org.onosproject.store.service.WallClockTimestamp;
 
 /**
  * Tests for {@link WallClockTimestamp}.