Force ruby-protocol-buffers to 1.5.x because 1.6.0 doesn't work
Only call after_commit on create for persisted records

Yes, ActiveRecord, this time you suck!
Merge pull request #5 from harrystech/dont_try_emitting_invalid_records

Only call after_commit on create for persisted records
Merge branch 'master' of github.com:harrystech/rails-pipeline into iron_pulling_subscriber