Sets the child class loader to parent class loader.

This prevents odd behavior in jdk 11 +

Fixes https://github.com/spring-cloud/spring-cloud-netflix/issues/3101

spring-cloud-context/src/main/java/org/springframework/cloud/context/named/NamedContextFactory.java

@@ -128,6 +128,9 @@ public abstract class NamedContextFactory<C extends NamedContextFactory.Specific
 		if (this.parent != null) {
 			// Uses Environment from parent as well as beans
 			context.setParent(this.parent);
+			// jdk11 issue
+			// https://github.com/spring-cloud/spring-cloud-netflix/issues/3101
+			context.setClassLoader(this.parent.getClassLoader());
 		}
 		context.setDisplayName(generateDisplayName(name));
 		context.refresh();

spring-cloud-context/src/test/java/org/springframework/cloud/context/named/NamedContextFactoryTests.java

@@ -19,6 +19,7 @@ package org.springframework.cloud.context.named;
 import java.util.Arrays;
 import java.util.Map;
 
+import org.assertj.core.api.Assertions;
 import org.junit.Test;
 
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
@@ -65,6 +66,13 @@ public class NamedContextFactoryTests {
 		AnnotationConfigApplicationContext fooContext = factory.getContext("foo");
 		AnnotationConfigApplicationContext barContext = factory.getContext("bar");
 
+		then(fooContext.getClassLoader())
+				.as("foo context classloader does not match parent")
+				.isSameAs(parent.getClassLoader());
+
+		Assertions.assertThat(fooContext).hasFieldOrPropertyWithValue("customClassLoader",
+				true);
+
 		factory.destroy();
 
 		then(fooContext.isActive()).as("foo context wasn't closed").isFalse();