Moved OAuth2 classes to authn package

gms/src/main/java/it/inaf/ia2/gms/CustomAuthenticationData.java → gms/src/main/java/it/inaf/ia2/gms/authn/CustomAuthenticationData.java

-package it.inaf.ia2.gms;
+package it.inaf.ia2.gms.authn;
 
 import java.util.Collection;
 import java.util.Map;

gms/src/main/java/it/inaf/ia2/gms/CustomIdTokenConverter.java → gms/src/main/java/it/inaf/ia2/gms/authn/CustomIdTokenConverter.java

-package it.inaf.ia2.gms;
+package it.inaf.ia2.gms.authn;
 
 import java.util.List;
 import java.util.Map;

gms/src/main/java/it/inaf/ia2/gms/LoginController.java → gms/src/main/java/it/inaf/ia2/gms/authn/LoginController.java

-package it.inaf.ia2.gms;
+package it.inaf.ia2.gms.authn;
 
 import java.security.Principal;
 import org.springframework.http.MediaType;

gms/src/main/java/it/inaf/ia2/gms/OAuth2Config.java → gms/src/main/java/it/inaf/ia2/gms/authn/OAuth2Config.java

-package it.inaf.ia2.gms;
+package it.inaf.ia2.gms.authn;
 
 import java.util.List;
 import org.springframework.beans.factory.ObjectProvider;