Send activation mail asynchronously.

Fix #112

No functional changes.

Author: php-coder

src/main/java/ru/mystamps/web/config/ServicesConfig.java

@@ -24,13 +24,15 @@
 import org.springframework.context.annotation.Configuration;
 import org.springframework.core.env.Environment;
 import org.springframework.mail.javamail.JavaMailSender;
+import org.springframework.scheduling.annotation.EnableAsync;
 
 // CheckStyle: ignore AvoidStarImportCheck for next 2 lines
 import ru.mystamps.web.dao.*; // NOPMD: UnusedImports
 import ru.mystamps.web.service.*; // NOPMD: UnusedImports
 import ru.mystamps.web.support.spring.security.SecurityConfig;
 
 @Configuration
+@EnableAsync
 public class ServicesConfig {
 
 	@Inject

src/main/java/ru/mystamps/web/service/MailServiceImpl.java

@@ -33,6 +33,7 @@
 import org.springframework.mail.javamail.JavaMailSender;
 import org.springframework.mail.javamail.MimeMessageHelper;
 import org.springframework.mail.javamail.MimeMessagePreparator;
+import org.springframework.scheduling.annotation.Async;
 
 import lombok.RequiredArgsConstructor;
 
@@ -50,6 +51,7 @@ public class MailServiceImpl implements MailService {
 	private final boolean testMode;
 
 	@Override
+	@Async
 	public void sendActivationKeyToUser(UsersActivation activation) {
 		Validate.isTrue(activation != null, "Activation must be non null");
 		Validate.isTrue(activation.getEmail() != null, "E-mail must be non null");