Added implements Serializable to eu.dnetlib.dhp.schema.oaf.Measure class

src/main/java/eu/dnetlib/dhp/schema/oaf/Measure.java

@@ -1,6 +1,7 @@
 
 package eu.dnetlib.dhp.schema.oaf;
 
+import java.io.Serializable;
 import java.util.List;
 
 import com.google.common.base.Objects;
@@ -8,7 +9,7 @@ import com.google.common.base.Objects;
 /**
  * Represent a measure, must be further described by a system available resource providing name and descriptions.
  */
-public class Measure {
+public class Measure implements Serializable {
 
 	/**
 	 * Unique measure identifier.