Upgrade to AppDynamics 3.8.+

A new version of AppDynamics is available and should be consumed in the Java
buildpack, this change does so.

[#74772312]
Merge branch 'cgfrost-master'

[resolves #68]
Upgrade New Relic to 3.8.+

A new version of New Relic is available and should be consumed in the Java
buildpack, this change does so.

[#74772414]
Merge branch 'cgfrost-master'

[resolves #69]