added endpoints to see all user without any auth for testing

MyINPulse-back/src/main/java/enseirb/myinpulse/service/AdminApiService.java

@@ -206,4 +206,8 @@ public class AdminApiService {
     public Iterable<User> getPendingUsers() {
         return this.userService.getPendingAccounts();
     }
+
+    public Iterable<Administrator> getAllAdmins() {
+        return this.administratorService.allAdministrators();
+    }
 }