Make sure spring-boot-test-support is not public

The `spring-boot-test-support` module is internal and is not deployed so
we should not offer public dependency management for it.

Closes gh-8165

spring-boot-dependencies/pom.xml

@@ -250,11 +250,6 @@
 				<artifactId>spring-boot-test-autoconfigure</artifactId>
 				<version>1.5.2.BUILD-SNAPSHOT</version>
 			</dependency>
-			<dependency>
-				<groupId>org.springframework.boot</groupId>
-				<artifactId>spring-boot-test-support</artifactId>
-				<version>1.5.2.BUILD-SNAPSHOT</version>
-			</dependency>
 			<dependency>
 				<groupId>org.springframework.boot</groupId>
 				<artifactId>spring-boot-actuator</artifactId>

spring-boot-parent/pom.xml

@@ -40,6 +40,12 @@
 	</ciManagement>
 	<dependencyManagement>
 		<dependencies>
+			<dependency>
+				<groupId>org.springframework.boot</groupId>
+				<artifactId>spring-boot-test-support</artifactId>
+				<version>1.5.2.BUILD-SNAPSHOT</version>
+			</dependency>
+
 			<!-- Additional Dependencies the consumers of spring-boot-dependencies
 				will generally not need -->
 			<dependency> <!-- deprecated but recent version required by 3rd party libs -->