title: Spring Boot ConfigurationProperties fail to initialize for integration testing
body: <p>Using gradle (3.4.1) with an integrationTest configuration, the tests using the ConfigurationProperties of Spring Boot (1.5.1.RELEASE) is failing to initialize even though the application initializes correctly (./gradlew bootRun).  The class annotated with ConfigurationProperties is similar to the following</p>
  
  <pre><code>@Component
  @ConfigurationProperties(prefix = "foo")
  @Validated
  public class AppConfiguration {
      @NonNull
      private URL serviceUrl;
      ...
  </code></pre>
  
  <p>The configuration file does have getters and setters.  The error that is generated is similar to the following</p>
  
  <pre><code>java.lang.IllegalStateException: Failed to load ApplicationContext
  ....
  Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'AppConfiguration': Could not bind properties to AppConfiguration
  ....
  Caused by: org.springframework.validation.BindException: org.springframework.boot.bind.RelaxedDataBinder$RelaxedBeanPropertyBindingResult
  Field error in object 'foo' on field 'serviceUrl': rejected value [null]; codes ...
  </code></pre>
  
  <p>The configuration class of the integration test is annotated as follows</p>
  
  <pre><code>@Configuration
  @ComponentScan(...)
  @EnableConfigurationProperties
  @EnableIntegration
  public static class ContextConfiguration {}
  </code></pre>