This change update the version of New Relic to 3.6.+

This change updates the versions of dependencies.

Previously, a Spring Boot WAR would cause both spring_boot and tomcat
to detect.  This change makes the discrimination stronger by only
allowing spring_boot to detect if it also has a start script.

[#70085176] [resolves #51]

[Completes #70085176]

Previously, the buildpack only enforced a single unique container in
the detect phase.  This meant that any time a buildpack was explicitly
specified (and detect skipped) it was possible to end up with an
ambiguous container choice.

This change ensures that the same logic for guaranteeing a unique
container is used in all phases.

[#70085176]

[Completes #70085176]

Previously, the documentation for the JAVA_OPTS framework wasn't clear
enough that a user could properly configure it without help.  This
change adds an example to that documentation to make it clearer.

[#69514724][resolves #49]

[Completes #69514724]

Previously there was no documentation around debugging the buildpack.
This lead to having to provide that information on mailing lists and
in issues.  This change adds documentation about debug logging and
running the buildpack locally.

[#69986486][resolves #50]

[Completes #69986486]