#437 Add email should not allow to change email

- Create separate test for adding email
- Check that no email is yet registered for add email

src/test/java/fr/xephi/authme/command/executable/email/AddEmailCommandTest.java

@@ -2,6 +2,7 @@ package fr.xephi.authme.command.executable.email;
 
 import fr.xephi.authme.command.CommandService;
 import fr.xephi.authme.process.Management;
+import fr.xephi.authme.util.WrapperMock;
 import org.bukkit.command.BlockCommandSender;
 import org.bukkit.command.CommandSender;
 import org.bukkit.entity.Player;
@@ -27,6 +28,7 @@ public class AddEmailCommandTest {
     @Before
     public void setUpMocks() {
         commandService = mock(CommandService.class);
+        WrapperMock.createInstance();
     }
 
     @Test
@@ -51,10 +53,10 @@ public class AddEmailCommandTest {
         given(commandService.getManagement()).willReturn(management);
 
         // when
-        command.executeCommand(sender, Arrays.asList("mail@example", "other_example"), commandService);
+        command.executeCommand(sender, Arrays.asList("mail@example", "mail@example"), commandService);
 
         // then
-        verify(management).performAddEmail(sender, "mail@example", "other_example");
+        verify(management).performAddEmail(sender, "mail@example");
     }
 
 }