Update YAML parsing test
[fixes #45652433] Remove deprecated VMC env variables
Update nodejs buildpack submodule

- Use forked heroku buildpack
- Use buildpack cache
Add git-core dependency to warden rootfs
Update run config vars for Logplex
Allow FileServer to serve buildpacks in git format
Update DirServer port in test to avoid collisions with warden
Bump buildpacks/vendor/nodejs:

Bleicke and Tim Labeeuw (1):
      Fix nodejs buildpack

Change-Id: If32bfeb2576b0fae460e7503029d6ec998251287
Merge branch 'master' into staging-environment-from-config-spike