Rename subscriber to member

src/main/java/eu/dnetlib/uoaauthorizationlibrary/security/AuthorizationService.java

@@ -31,7 +31,7 @@ public class AuthorizationService {
      *
      * Id = EE, EGI, etc
      * */
-    public String subscriber(String type, String id) {
+    public String member(String type, String id) {
         return type.toUpperCase() + "_" + id.toUpperCase();
     }
 }