SpringBoot Document how to configure Maven's Failsafe plugin when not using spring-boot-starter-parent

A documentation fix for #25473 to document how to configure maven's failsafe plugin when not using spring boot starter parent pom.

Comment From: wilkinsona

Thanks for the pull request, @robert-smith-911. Unfortunately, this isn't quite what I had in mind. Rather than changing the configuration of spring-boot-maven-plugin, I think we should document the same setup as spring-boot-starter-parent gives you. It configures Failsafe to use the compiled classes rather than the repackaged jar:

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-failsafe-plugin</artifactId>
    <configuration>
        <classesDirectory>${project.build.outputDirectory}</classesDirectory>
    </configuration>
</plugin>

AFAIK, using this approach also means that there's no custom configuration required when the module path's in the picture.

Would you like to update your proposal along these lines?

Comment From: robert-smith-911

Aha sure @wilkinsona no problem!

Comment From: snicoll

@robert-smith-911 how is it going? Would you have time to update this PR?

Comment From: robert-smith-911

@snicoll Yes sir just got busy at work, doing it today thanks for the reminder

Comment From: robert-smith-911

@snicoll @wilkinsona How's this?

Comment From: wilkinsona

Thanks very much, @robert-smith-911. If you're interested a polished the proposed changes a little bit, primarily to move the updates into the integration testing section of the documentation.

Comment From: robert-smith-911

@wilkinsona sure!