Bump ruby buildpack and update rubies

dea shortlog f63aa48..976a09a
Bleicke and Maria Shaldibina (1):
      Bump ruby buildpack

David Sabeti and Scott Calvert (3):
      Change Procfile and Raketask to start-up log-server properly
      Add app_id to valid_staging_attributes
      Extend timeout window for PortOpen healthcheck spec

Max Brunsfeld and Scott Calvert (7):
      In dev VM, don't put warden rootfs in /tmp
      Optimize erlang cookbook
      Remove log server from procfile
      Setup Vagrant port forwarding for logplex REST API.
      Extract nats helper module for integration specs
      Add initial staging integration test
      Temporarily don't run tests that need warden on ci

cf-frameworks (1):
      Merge pull request #3 from yssk22/request/script-hooks

yssk22 (3):
      Add hook script capability on droplet start/stop.
      Change 'stop' hooks timing since 'after_stop' does not make after warden container stopped...
      added stop script test and refactoring of tests for script hooks.