Update flattened POM elements

Update flattened POM rules to satisfy maven central
requirements.

Fixes gh-12290

spring-boot-project/spring-boot-dependencies/pom.xml

@@ -22,6 +22,14 @@
 	<scm>
 		<url>https://github.com/spring-projects/spring-boot</url>
 	</scm>
+	<developers>
+		<developer>
+			<name>Pivotal</name>
+			<email>info@pivotal.io</email>
+			<organization>Pivotal Software, Inc.</organization>
+			<organizationUrl>http://www.spring.io</organizationUrl>
+		</developer>
+	</developers>
 	<properties>
 		<!-- Dependency versions -->
 		<activemq.version>5.15.3</activemq.version>

spring-boot-project/spring-boot-starters/spring-boot-starter-parent/pom.xml

@@ -270,10 +270,13 @@
 						<configuration>
 							<updatePomFile>true</updatePomFile>
 							<pomElements>
-								<pluginManagement>keep</pluginManagement>
 								<parent>expand</parent>
-								<dependencyManagement>keep</dependencyManagement>
+								<name>keep</name>
+								<description>keep</description>
+								<url>expand</url>
 								<properties>keep</properties>
+								<pluginManagement>keep</pluginManagement>
+								<dependencyManagement>keep</dependencyManagement>
 								<build>keep</build>
 							</pomElements>
 						</configuration>

spring-boot-project/spring-boot-starters/spring-boot-starter-parent/src/main/xslt/post-process-flattened-pom.xsl

@@ -18,4 +18,5 @@
 	<xsl:template match="/m:project/m:groupId" />
 	<xsl:template match="/m:project/m:version" />
 	<xsl:template match="/m:project/m:build/m:plugins" />
+	<xsl:template match="/m:project/m:licenses" />
 </xsl:stylesheet>