Minor - code householding (tests)

- Remove redundant uses of WrapperMock
- Use assertThat() from JUnit, not hamcrest
- Use hamcrest Matchers everywhere (not BaseMatchers etc.)
- Favor Mockito's argThat() over using ArgumentCaptor (more succinct)
- Delete useless test classes

src/test/java/fr/xephi/authme/command/executable/logout/LogoutCommandTest.java

@@ -2,21 +2,18 @@ package fr.xephi.authme.command.executable.logout;
 
 import fr.xephi.authme.command.CommandService;
 import fr.xephi.authme.process.Management;
-import fr.xephi.authme.settings.Settings;
-import fr.xephi.authme.util.WrapperMock;
 import org.bukkit.command.BlockCommandSender;
 import org.bukkit.command.CommandSender;
 import org.bukkit.entity.Player;
 import org.junit.Before;
 import org.junit.Test;
-import org.mockito.ArgumentCaptor;
 
 import java.util.ArrayList;
 import java.util.Collections;
 
-import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.containsString;
 import static org.mockito.BDDMockito.given;
+import static org.mockito.Matchers.argThat;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.verify;
@@ -30,8 +27,6 @@ public class LogoutCommandTest {
 
     @Before
     public void initializeAuthMeMock() {
-        WrapperMock.createInstance();
-        Settings.captchaLength = 10;
         commandService = mock(CommandService.class);
     }
 
@@ -46,9 +41,7 @@ public class LogoutCommandTest {
 
         // then
         verify(commandService, never()).getManagement();
-        ArgumentCaptor<String> messageCaptor = ArgumentCaptor.forClass(String.class);
-        verify(sender).sendMessage(messageCaptor.capture());
-        assertThat(messageCaptor.getValue(), containsString("only for players"));
+        verify(sender).sendMessage(argThat(containsString("only for players")));
     }
 
     @Test