TestContext: define PropertySourcesPlaceholderConfigurer as static.

Fix the warning from Spring Test Framework:
2016-08-22 23:30:28.746  WARN   --- [           main] o.s.c.a.ConfigurationClassEnhancer:
@bean method TestContext.getPropertySourcesPlaceholderConfigurer is non-static and returns an object
assignable to Spring's BeanFactoryPostProcessor interface. This will result in a failure to process
annotations such as @Autowired, @resource and @PostConstruct within the method's declaring
@configuration class. Add the 'static' modifier to this method to avoid these container lifecycle
issues; see @bean javadoc for complete details.

No functional changes.

Author: php-coder

src/test/java/ru/mystamps/web/config/TestContext.java

@@ -22,11 +22,13 @@
 import org.springframework.context.support.PropertySourcesPlaceholderConfigurer;
 import org.springframework.core.io.ClassPathResource;
 
+// CheckStyle: no, it isn't utility class, it's a configuration with a single bean
+@SuppressWarnings("checkstyle:hideutilityclassconstructor")
 @Configuration
 public class TestContext {
 
 	@Bean
-	public PropertySourcesPlaceholderConfigurer getPropertySourcesPlaceholderConfigurer() {
+	public static PropertySourcesPlaceholderConfigurer getPropertySourcesPlaceholderConfigurer() {
 		PropertySourcesPlaceholderConfigurer configurer =
 			new PropertySourcesPlaceholderConfigurer();
 		configurer.setLocations(