Build deployment environment but not development environment.
Build deployment environment but not development environment.

This includes:
* Run bundler with deployment mode
* Sepcify -E production when rackup.

dazuma/ruby-docker,GoogleCloudPlatform/ruby-docker,dazuma/ruby-docker,GoogleCloudPlatform/ruby-docker,GoogleCloudPlatform/ruby-docker,dazuma/ruby-docker,dazuma/ruby-docker,remi/ruby-docker,GoogleCloudPlatform/ruby-docker