Document alternative modes of using the buildpack

There is no documentation about the different ways that the buildpack can be
used. This commit add documentation about expert mode and offline buildpacks.

[#76619826]
Further changes to expert mode documentation

These changes bring the submission in line with the suggestions in
issue #96.

[#76619826]
Merge branch 'cgfrost-76619826-document-expert-mode'

[resolves #98]
New Relic 3.+

This change updates the dependency version of New Relic to 3.+.

[#78809276]
Merge 78809276-new-relic-3.+ to master

[Completes #78809276]
AppDynamics 3.9.+

This change updates the dependency version of AppDynamics to 3.9.+.

[#78993216]
Merge 78993216-app-dynamics-3.9.+ to master

[Completes #78993216]
Ruby 2.1.3

This change updates the Travis configuration to test against 2.1.3.
Update dependencies

This change updates all of the buildpack's dependencies.  This
necessitated some changes to the code as part of the rubocop upgrade.

[#78553124]
Merge 78553124-formatting-method to master

[#78553124]
Tomcat 8

This change makes Tomcat 8 the default version of Tomcat used by Servlet-based applications.

[#78317410]
Merge 78317410-tomcat-8 to master

[Completes #78317410]
Conditional Tomcat Configuration

In an earlier, naive, attempt to make Tomcat 8 the default, the code did not take into account that certain
configuration options have changed.  This commit fixes the code so that resource linking is done properly depending on
whether Tomcat 8 or pre-Tomcat 8 is used and only adds the JasperListener to pre-Tomcat 8 is used.

[#78317410][resolves #95]
Merge 78317410-tomcat-8 to master

[Completes #78317410]
Output killjava.sh to console

Previously, the killjava.sh script output was directed to a file.  This
worked previously with the crashlogs command to ensure that users could
see what had gone wrong.  With the removal of the crashlogs command,
this command no longer worked properly.  This change updates the script
to output to the console instead, where the output will be picked up by
loggregator.

[#57139852][resolves #79]
Merge 57139852-oom-loggregator to master

[Completes #57139852]
Custom Download CA Certificates

Previously, when a download was done using the DownloadCache using
HTTPS, it was assumed that the SSL certificate presented by the server
could be validated with the CA store packaged with OpenSSL.  This
didn't work for servers that included self-signed, or non-standard CA
-based certificates.  This change updates the DownloadCache to allow a
user to present a collection of additional CA certificates.  By
creating a /resources/ca_certs directory and placing the certificates
(in PEM format) within it, the DownloadCache will use the provided
certificates during verification.
Merge branch 'ca-certs'