Filter integration tests to only pom folders

Update invoker configuration so that only folders with a pom.xml file
are invoked. This helps when switching between the 1.1.x and master
branches since empty folders left by git no longer fail the build.

Author: philwebb

spring-boot-integration-tests/pom.xml

@@ -51,6 +51,9 @@
 							<localRepositoryPath>${project.build.directory}/local-repo</localRepositoryPath>
 							<skipInvocation>${skipTests}</skipInvocation>
 							<streamLogs>true</streamLogs>
+							<pomIncludes>
+								<pomInclude>*/pom.xml</pomInclude>
+							</pomIncludes>
 						</configuration>
 						<executions>
 							<execution>